Taiwan Strait Crisis To Europe

There is an emergent policy consensus within the US that the period from 2027 to the early 2030s represents one of acute danger for Taiwan. This view was captured by former Commander US Indo-Pacific Command Admiral Philip Davidson, who predicted that an invasion of Taiwan by China is possible by 2027, a view echoed by other senior figures.

If the US must commit substantial forces to deterrence or defence in the Indo- Pacific, this will have significant second-order effects within Europe. By the end of this decade, the partial reconstitution of Russian forces is likely, as is the growth of Russian capacity with respect to capabilities, such as nuclear submarines, which have not been impacted by the conflict in Ukraine.

This report examines which US capabilities will be most relevant in an Indo- Pacific contingency, as well as which capabilities among these are fungible – that is, of utility both in Europe and in a Taiwan contingency. Its purpose is to identify areas where gaps are most likely to emerge in Europe’s defensive posture as a consequence of the potential reallocation of US capabilities. Its major findings are that:

• To a large extent, the question of how an invasion of Taiwan might impact deterrence in Europe depends on US military strategy in the Indo-Pacific. A denial-orientated strategy creates far fewer gaps in a two-theatre posture than one that requires extensive strikes on the Chinese mainland, and is also likely to be more feasible militarily.

• The suppression of enemy air defences (SEAD) involves very different capabilities in the two regions, as the critical assets that China will need to defend its amphibious shipping will be defended by air and maritime platforms, rather than by ground-based transport erector launchers. Munitions such as the AARGM, which are optimised against elusive targets, can be allocated to European defence if policy allows for it and if European air forces are adequately prepared for SEAD, without undermining the US in Asia.

• Integrated air and missile defence represents an especially fungible capability, and one that will be heavily strained by a two-theatre scenario. This is, however, more true of systems that enable tactical ballistic missile defence (BMD) and defence against air-breathing threats than it is for upper tier systems that enable theatre-level BMD. Russia’s lack of capability in intermediate-range ballistic missiles or medium-range ballistic missiles, and the time it would take to develop and scale these, mean that the Russian and Chinese missile arsenals present different problem sets.

• Resilient C4ISR and the organisational capital to enable its employment are a concern across both theatres.

• While land forces are a less fungible capability, many of the enablers on which they depend, in terms of airlift and sealift as well as air defences, may be drawn on in the Pacific.

Introduction

Over recent years, predictions have been made by several senior US figures, including the former US Commander Indo-Pacific Command Admiral Philip Davidson and CIA Director William Burns, that China is likely to either invade Taiwan by 2027 or, at a minimum, wishes to have the option of doing so. This prediction, the so-called “Davidson Window”, has been reinforced by analysis that suggests that the period between the mid-2020s and the early 2030s represents one of acute vulnerability for Taiwan. One of the major factors behind this assessment is the fact that US capabilities in several key areas will reach a nadir in the late 2020s as older aircraft, surface vessels and submarines are retired, with replacement rates resulting in capability gaps that will not be filled until well into the 2030s.

This could mean, as some have argued, that the US will lack the capacity by itself to deter a peer and a near-peer competitor (China and Russia) simultaneously. If true, this would have considerable second-order effects on the deterrence of Russia in Europe if Russia either coordinated action with China or acted opportunistically during a crisis in Asia. While it is difficult to forecast with any certainty Russian decision-making during a hypothetical conflict over Taiwan, and much depends on the course of Russia’s war in Ukraine, there would be at least one structural incentive for Moscow to attempt to reorder Europe’s political arrangements during a clash in the Indo-Pacific. Russia could enjoy a transient window of military advantage over European states that face critical shortfalls in areas such as integrated air and missile defence (IAMD) and munitions stockpiles – even though longer-term trends would suggest its prospects for competing militarily with NATO are dim. Declining powers that face a combination of short-term opportunity and long-term decline tend to be especially risk acceptant. But this does not mean that a crisis in East Asia will automatically have second-order effects in Europe, as this will be determined by many contingent factors. Nevertheless, there are grounds for an assessment of the minimal capabilities required to maintain conventional deterrence within Europe in a context of US resources being severely overstretched.

Irrespective of how likely the prospect of a war in East Asia in the late 2020s might be, identifying which capability gaps could emerge within the European theatre if there were such a war can help to assess both those areas where the dependence of NATO on US capabilities represents an immediate point of fragility in the Alliance’s defence posture, and which dependencies can be offset by Europe on a longer-term basis.

This is important because not all military capability is fungible – that is, of utility both in Europe and in a Taiwan contingency. Factors such as the geography of a theatre and the operational plans that underpin a deterrent posture in each theatre have considerable salience. For example, it is unclear whether armour and multiple launch rocket systems (MLRS) have as much utility in a Sino-American conflict – a primarily maritime theatre – as they do in Europe (although both capabilities have a role in each theatre). It is for this reason that leaders have historically often engaged in target- or component-specific balancing – attempting to offset the component of an opponent’s power deemed most threatening to them, rather than the full suite of capabilities.

This bears consideration for several reasons. First, although there has been much discussion of potential US overstretch in the event of a two-war scenario, there is room for a more detailed discussion regarding precisely in which areas the US would find itself most heavily strained. Second, individual combatant commands typically draw up regional plans which, although not isolated from a wider global context (especially since the adoption of the 2018 National Defense Strategy), are primarily informed by regional considerations. In a context where historical two-war planning assumptions had been replaced by one-major-war assumptions, the question of competition for resources, both among combatant commands and between the US’s NATO and other commitments, could be safely ignored. This is no longer the case. In this regard, open source academic work can contribute to an understanding of the shared dependencies of individual combatant commands, as planning for multiple theatres again becomes de rigueur. Third, while European members of NATO and organisations such as SHAPE (Supreme Headquarters Allied Powers Europe) do have access to US planning assumptions to inform NATO’s Concept for Deterrence and Defence of the Euro-Atlantic Area (DDA) family of plans, the very complexity of such plans makes assessing regional requirements complex in its own right, and leaves minimal spare capacity for secondary assessments about how dynamics in the Indo-Pacific might impact Europe. As such, a discussion of the interrelationships between theatre-level strategies can be informed by a wider public discussion.

This Whitehall Report summarises the findings from several roundtables held by RUSI in London in December 2023 with subject matter experts from a number of allied countries, focusing on European deterrence. It also summarises the results from formal combat modelling using tools such as Monte Carlo simulations, and desk-based analysis of historical analogous case studies and operations. The report does not seek to assess the precise quantity of any individual capability required in either Europe or the Indo-Pacific (although plausible estimates are used throughout). Rather, the report focuses on the question of how fungible specific capabilities are, and as a result how likely competing demand signals for their deployment would be.

Chapter I examines the requirement from the Indo-Pacific in order to identify which US capabilities will be most critical in the event of a Taiwan contingency. Chapter II details the impact of this demand signal on the Allied posture in Europe. Its purpose is to examine which of the capabilities most needed in the Pacific are also relevant to European deterrence, and where the absence of US capabilities in Europe is both most likely and most impactful in the event of an Indo-Pacific contingency. The report concludes with a summary of the areas in which capabilities are likely to be rapidly exhausted by a contingency spanning two theatres and where they can be rationally allocated across two theatres without generating overstretch.

I. What Determines the Demand Signal in the Indo-Pacific?

This chapter focuses on the contours of a future conflict over Taiwan. It seeks to identify the specific US military capabilities that will be in greatest demand in the Pacific should such a conflict occur. It also aims to establish a basis for comparing the resource demands of the European and Indo-Pacific theatres.

The question of which US assets will be most heavily stretched by the occurrence of two simultaneous conflicts in the Indo-Pacific and Europe will be determined by several key variables. Among them are:

• The preferred Chinese strategy.

• The preferred US response.

The approach taken by China’s leaders to achieve any eventual military resolution of the Taiwan Strait question will be a major determinant of the options available to US decision-makers and thus the demands placed on their resources. There are several options available to China regarding Taiwan: a full-scale invasion; a blockade; or a limited-aims seizure of a specific outlying island, such as Qemoy or Matsu.

This report restricts its focus to a full-scale invasion for two reasons. First, this is the scenario most frequently discussed in the context of the purported “Davidson Window”. Second, there are few (if any) cases of states achieving decisive effects through either a blockade or a limited aim. While the authors regard the focus on a full-scale invasion to be defensible, it does narrow the focus of the report. It should also be noted that the report focuses specifically on the conventional balance. The subject of how China’s growing nuclear arsenal will impact deterrence in both theatres will, however, be the focus of subsequent RUSI research.

Second, there is the question of the US preferred response. While this cannot be ascertained with certainty, the feasibility of various options is easier to scope. It looks increasingly unlikely that the original aims of concepts such as AirSea Battle in 2010, which would have seen the US conduct strikes at scale against the Chinese mainland, are viable. Some estimates suggest that a strike campaign to both blind China’s C4ISR and disrupt its major bases could, for example, require up to 28,000 precision-guided munitions for initial strikes and could – based on campaigns such as Operation Desert Storm – involve the targeting of 40,000 aim points. Not only is the sustainability of such a campaign questionable in terms of munitions stocks alone, but the ability of the US Navy and US Air Force (USAF) to maintain the required operational tempo to achieve it is debatable, if one assumes that the risk from China’s long-range strike capabilities means that forces must operate from greater distances. The likely expansion of China’s nuclear arsenal, and the fact that at least some elements of this arsenal will share both bases and command-and-control (C2) structures, will act as constraints in any strike campaign against the mainland. Nuclear weapons do not necessarily make a nation’s territory inviolable, but they do have the effect of making an opponent’s targeting decisions slower and more deliberate – which runs contrary to the tempo of activity required by a strike campaign at large scale.

As such, it is presumed that the most viable approach likely to be available to the US is achieving sea denial within the Taiwan Strait. Since the loss of a considerable part of its amphibious lift capability would necessarily condemn a Chinese invasion to failure, the US does not necessarily need to strike the mainland at scale to defeat an invasion. The cost in munitions and the escalatory risk inherent in sea denial are considerably more manageable. A denial campaign need not eschew strikes on the mainland, but these strikes would probably occur on a more limited scale and only when necessary to enable attacks on China’s amphibious assets.

Third, the position of states such as Japan will be of considerable significance. While support in line with the obligations Japan accepted under the 1997 US–Japan defence guidelines is likely, deeper involvement by Japan would have considerable effects, given that the Japan Maritime Self-Defense Force (JMSDF) fields what is still the region’s largest force of destroyers (other than that of the US Navy), as well as 22 attack submarines.

Resource Demands of a Taiwan Invasion

The Opening Stage of an Invasion

Any Chinese assault on Taiwan would be preceded both by political indicators and by a joint firepower strike operation combining ballistic missiles, cruise missiles and fixed-wing aircraft in both suppressive and attack roles against airbases, surface-to-air missile (SAM) systems and command nodes on both Taiwan and, in all likelihood, US airbases such as Kadena in Japan. A People’s Liberation Army (PLA) joint firepower strike operation is closely modelled on USAF operations during the Gulf War and would probably comprise functionally similar elements, although it is likely that the initial deep penetration provided by the F-117 would instead be provided by short-range ballistic missiles (SRBMs) such as the DF-15, and hypersonic glide vehicles such as the DF-17.

China’s Amphibious Capabilities

A Chinese amphibious assault on Taiwan could then develop in several ways. The PLA could opt for an assault on a relatively broad front involving all or most of the 14 or so beaches on Taiwan that can support a landing at battalion scale or larger. This would have the advantage of imposing uncertainty regarding where to concentrate defending Taiwanese troops, much as the choice of five landing beaches and elaborate preceding deception operations set the conditions for Operation Overlord. Taiwan’s beaches are relatively narrow, and the PLA’s amphibious doctrine calls for combined arms battalions (the basic unit of force of the People’s Liberation Army Ground Force (PLAGF) and the People’s Liberation Army Navy Marine Corps (PLANMC)) to occupy 2–4 km in the assault, making an attack on multiple axes likely given the constrained geography of each individual landing site. That said, it should be noted that even if comparable in success to the 1991 Gulf War, a PLA joint firepower operation would last for several weeks and take more than a week to achieve air superiority (based on the air campaign during Desert Storm), giving Taiwan’s defenders time to prepare approaches to the island with several hundred mines in a short timeframe (assuming that Taiwan’s minelayers and submarines are not destroyed in port early). The People’s Liberation Army Navy (PLAN) fields a robust force of more than 40 mine countermeasure vessels, but these ships would have limited organic defences against surviving Taiwanese anti-ship cruise missile (ASCM) batteries. This in turn could incentivise an invasion plan that focuses on a smaller subset of beaches requiring fewer Q-routes (safe routes through minefields), making it less susceptible to disruption if too many mine countermeasure vessels are sunk in any one channel.

Nevertheless, the PLAN will in the immediate term face limitations in terms of dedicated amphibious lift capabilities. China has the capability to field nine Type 071 landing platform docks, which can carry 65 armoured vehicles, as well as a further four Type 075 landing helicopter docks (LHDs), which can support amphibious assault with assault craft launched from their well decks and can also carry vertical lift assets (and, in the future, vertical take-off and landing UAVs). In addition, the PLAN fields a larger number of older amphibious vessels, such as the Type 072A and the Type 072III, which can carry 250 troops and 10 armoured vehicles each. Collectively, the PLAN fields 49 landing ship tanks across the Eastern and Southern theatre commands, with 57 across the force. Given that the PLAN built four Type 075s between 2019 and 2024, it is likely that it could expand its fleet of LHDs to roughly double by the end of the decade. However, even accounting for a considerable expansion, the size of an initial assault wave would be limited, given that even the Type 075 LHD could in principle carry most (but not all) of a PLA combined arms battalion’s armour, vehicles and troops. A battalion’s organic capabilities must nevertheless be carried on multiple vessels, and so the landing of a single battalion is expected to occur in several waves. Even a larger future PLAN amphibious lift capability would, then, have limited excess capacity relative to the magnitude of its tasks, and the loss of a portion of the force would condemn an invasion to failure.

It has been pointed out that a focus on dedicated landing vessels may substantially undervalue the PLAN’s aggregate strength because it ignores China’s efforts to prepare its civilian shipping industry to support amphibious operations in the Taiwan Strait. When China’s dual-use civilian vessels are incorporated into an analysis, the PLAN’s aggregate freight capacity almost trebles to 1.1 million tons. Based on assumptions derived from previous amphibious operations, this would imply an aggregate capability to move around 12 combined arms brigades across the Taiwan Strait in a single wave – in effect, all the amphibious-capable brigades of the PLANMC and the PLAGF.

There are, however, outstanding questions regarding the use of non-dedicated vessels for sealift, although the PLAN does appear to be testing their potential for assault roles in exercises. Among them is whether such vessels are more suited to functions for joint logistics rather than the shore, which still appears to be the primary role for which the PLAN is rehearsing. The possibility that civilian vessels could considerably expand China’s amphibious lift therefore cannot be excluded. On balance, however, the loss of a significant part of an already limited fleet of dedicated amphibious vessels should condemn an invasion to failure, as these vessels will be critical to the success of an initial assault wave.

Airborne Forces in an Island Landing Campaign

The People’s Liberation Army Air Force (PLAAF) could also play a role in any amphibious assault, but only if China’s joint firepower operation succeeds. The PLAAF’s Airborne Corps comprises six combined arms brigades and one special operations forces brigade, supported by a fleet of 31 Y-20 transport aircraft and 20 Russian-made IL-76 airlifters, and a larger number of light Y-9 aircraft. These airborne brigades and their constituent battalions are equipped with the ZBD-03 armoured fighting vehicle (AFV) and both the 122-mm PL-96 and the 107-mm PH-63 MLRS. An airborne brigade’s table of organisation and equipment is comparable to that of a PLA medium combined arms brigade. There are, however, considerable differences between individual brigades. The 127th, 128th and 131st Brigades, for example, appear to be light motorised units equipped with all-terrain vehicles and can be paradropped. In addition, the 130th Combined Arms Brigade is air-assault capable and supported by roughly 41 Z-8KA, Z-9WZ and Z-10 utility, transport and attack helicopters. The heavier brigades equipped with the ZBD-03 AFV would probably be moved by IL-76 or Y-20 and would thus require motorised and air-assault units to have secured access to an airfield. In addition, the PLAGF fields two air-assault brigades that have exercised in tandem with the PLAAF Airborne Corps since 2021. According to PLA textbook The Science of Campaigns, airborne forces can support preliminary operations, such as deception and decapitation, or can enable the operational dislocation of an opponent through landings in depth and assault operations, where they would be a first echelon force tasked with seizing beach-heads. The Science of Campaigns is, however, realistic about the limitations of airborne assault, noting that absolute air superiority is required to enable airborne assaults, and that they should be treated as an essentially discretionary activity to be supported by four waves of attack aircraft for every one wave of transport. In effect, for airborne units to land freely, the PLAN and PLAAF require the ability to operate freely over Taiwanese airspace to an extent that would allow the suppression of both pop-up SAM threats and man-portable air defence systems (MANPADs). If this is lacking, it will prove difficult to seize airfields long enough for the heavier elements of a force to move, as illustrated by the Russian Airborne Forces at Hostomel.

The Determinants of Success for Attacker and Defender

Even accounting for civilian lift and airborne forces, a considerably larger PLA first wave would be small relative to the Taiwanese armed forces, which would field a 90,000-strong defending land force. The historical average force-on-force ratio (1941–2002) for successful amphibious assaults is 1:5.29. There are notable exceptions, including the fall of Crete (1940) and the assault on Saipan (1944). In each of these cases, the success of the assault was enabled primarily by absolute air superiority on the side of the attacker. It is thus not unreasonable to conclude that anything short of air supremacy is a defeat condition for a PLA amphibious assault. Moreover, the small size of the force relative to the defender means that even limited losses of amphibious vessels can condemn an invasion to failure.

As such, the dominant consideration will be whether the PLAN and the PLAAF can both secure air supremacy around Taiwan (at least for a time) and protect amphibious vessels against non-aerial methods of attack (mines and submarines).

The first determinant will be whether the PLA is able to create an effective joint engagement zone (JEZ) in and around the Taiwan Strait to minimise the effects of cruise missile attacks on its dedicated amphibious vessels, which will remain crucial to ultimate success, even if augmented with civilian shipping. The PLAN currently fields 33 theatre air-defence vessels, such as the Type 052D guided missile destroyer (DDG) and the Type 055, and could field up to 50 by the end of the decade, based on the construction rates achieved by China in recent years. Vessels such as the Type 052D are equipped with the Type 346A active electronically scanned array antenna (AESA) radar and can carry long-range SAMs such as the HHQ-9, as well as shorter-range 16-km HHQ-6 missiles. China’s Type 055 cruiser is also equipped with an AESA and can quad pack shorter-range HHQ-6 SAMs in some of its 112 vertical launching system cells. Vessels such as the Type 052D and the Type 055 would likely be deployed in surface action groups (SAGs) both in the Taiwan Strait and east of Taiwan to create a layered air-defence network. Of particular significance to the PLAN would be closing off channels such as the Bashi Channel and northern approaches to the Taiwan Strait, through which ASCMs can travel without prior deconfliction with Taiwan’s own air defences.

In addition, the PLAAF is likely to fly patrols over the Taiwan Strait. Since the mid-2000s, Chinese fighters such as the J-10, J-11 and J-16 have fielded the PL-12, an air-to-air missile (AAM) with a profile comparable to the AIM-120, which probably uses an imported seeker from the Russian R-77 AAM. This interceptor will probably be replaced by the PL-15, a longer-range missile with an onboard AESA radar comparable to the AIM-120C/D AAM. While not primarily built for cruise missile intercept in the vein of the Russian MIG-31, these aircraft can contribute to defensive counter-air missions in and around the Taiwan Strait.

By contrast, many of China’s ground-based SAMs would have limited utility in protecting amphibious vessels. While the notional range of a system such as the HQ-9 SAM theoretically allows it to cover most of the Taiwan Strait, in practice constraining factors such as the limitations imposed on radar by the curvature of the Earth when tracking low altitude targets will come into play. Airborne Warning and Control Systems (AWACS) such as the KJ-2000 could be used to provide line of sight, but as illustrated by the Russian air campaign in Ukraine, AWACS can be vulnerable to electronic attack and, by virtue of being large high-flying aircraft, can also be intercepted at long distances by the long-range SAMs on US DDGs. Russia also struggles to cue ground-based air defence systems with its A-50 Mainstay AWACS due to the fact that data transfers are mediated by combined arms army headquarters, a problem that may also be inherent in PLA C2, in which a joint theatre command plays a central role. That said, Russian air defences in Ukraine have scored very long-range intercepts against low-flying aircraft cued by S-band radar, such as the Podolet-K1 radar, as well as by passive coherent location, and it is likely that Chinese ground-based SAMs can rely on their own onboard radar to conduct engagements based on less detailed feeds.

While this is possible, it is unlikely to be a reliable mechanism for defeating low-flying ASCMs. As such, the utility of long-range SAMs such as HQ-9 and S-400 for maritime air defence is likely to be attenuated. Shorter-range systems, such as the 40-km HQ-16 SAM, are of even more limited utility, although these systems will play an important role in protecting amphibious vessels from being struck in port, either by Taiwanese systems such as the Hsiung Feng-II anti-ship missile system, or by US standoff munitions.

China could attempt to secure islands such as Penghu ahead of an assault on Taiwan and build them into air-defence bastions, although their limited space and mountainous geography, as well as their proximity to the mainland (and thus a range of attack vectors), are complicating factors. Notably, as recently as a decade ago the PLA doctrinally subdivided zones of responsibility for SAM fighter aircraft and vessels and emphasised SAM ambushes and point defence for ground-based air-defence systems. While this might have changed, the limitations of China’s capacity to integrate the different service level air-defence capabilities that drove this delineation may persist. Even if cued by a US-style cooperative engagement capability, the PLAAF ground-based air-defence systems would depend on maritime and air assets for cueing and could not play an independent role.

If a Chinese integrated air defence system (IADS) comprising primarily maritime and air elements performs robustly, the number of cruise missiles required to inflict crippling damage on an invading fleet will be substantial. For example, a 2009 RAND study calculated that roughly 52 out of a notional force of 100 PLA amphibious vessels, which China was assumed to have by 2020 (larger, it turns out, than the PLAN today possesses, but perhaps a realistic figure for 2027–30), would need to be sunk or mission killed to prevent the PLA from concentrating roughly 60,000 troops on Taiwan over several trips. The historical average hit rate for cruise missiles against defended targets is around 0.26, and it is likely that, at least for larger vessels, more than one ASCM will be required to achieve either a mission kill or a sinking. A success rate of 80% is also the peak rate achieved by the land-based Ukrainian IADS against missiles such as the Kalibr and the KH-101 cruise missile around Kyiv. Some studies suggest the effectiveness of an Aegis-like system against cruise missiles is probably higher, with vessels enjoying a single-shot probability of kill (SSPK) of 0.95, though this may not be realistic under combat conditions. Moreover, there are factors other than active defence that are relevant. For example, soft-kill measures against missile seekers with the aim of either jamming or spoofing them are likely to increase in effectiveness as a conflict progresses, since the PLAN will be exposed to the seeker frequencies of US missiles. The PLA will use maritime militia vessels as decoys to generate maritime clutter.

Drawing on US Capabilities

As such, even a strategy focused on the relatively modest goal of sea denial would see a significant section of US anti-surface warfare capabilities drawn to the region. It is not inconceivable that up to 1,000 ASCMs would be required by the US and Taiwan to cripple an invasion fleet. The US plans to export 400 Harpoon ASCMs to Taiwan and will field 450 long-range anti-ship missiles (LRASMs) by the end of the decade, along with older Harpoon ASCMs and joint air-to-surface standoff missiles (JASSMs), which potentially have anti-ship functionality. However, the utility of the JASSM as an anti-ship missile is open to debate, while stocks of Harpoon will be nearing the end of their service lives, resulting in the US facing a shortfall.

Other anti-ship options are also possible, including the SM-6, the Naval Strike Missile (in service with the US Marine Corps) and Maritime Strike Tomahawk. This adds considerable capacity as, to use one example, 825 SM-6 missiles have been delivered to the US Navy to date. However, many of these systems are dual use (SM-6 is also an air-defence asset, while Tomahawk has a land-attack role), so their employment as anti-ship missiles involves trade-offs in an environment where US vessels will come under heavy attack from the PLA’s missile arsenal.

Limiting Factors

Launch platforms and tempo of activity represent a particularly acute limiting factor, given the risks that platforms such as vessels and aircraft take if they operate within a Chinese anti-access area-denial system comprised of long-range strike assets such as the DF-17 hypersonic boost glide missile and the DF-21D anti-ship ballistic missile (although the range of cruise missiles such as the LRASM mitigates these risks somewhat). The tempo at which successful strikes would need to be delivered would strain the US military, but this will be compounded if aircraft such as the F/A-18 (one of the platforms on which the LRASM is carried) have to take off from greater distances and rely on enablers such as tankers, against which the PLA is optimising fighter aircraft such as the J-20 to conduct long-range intercepts.

Other Options

Anti-ship missiles are not the only means of sinking vessels available to the US and Taiwan. Although the relatively shallow waters of the Taiwan Strait are not optimal for nuclear attack submarines (SSNs), attack submarines such as the Seawolf class are built to operate in shallow waters if necessary. Moreover, the layout of an air-defence screen for a Chinese landing force would probably require at least some Chinese surface combatants to operate in what PLA doctrine describes as a “forward-edge” defence role beyond the first island chain, in which SSNs are likely to be considerably more lethal.

More modern Chinese ships, such as the Type 055, are equipped with credible sensor suites, including both hull-mounted and towed array sonar, as well as the capacity to host two Z-20F helicopters, and some Chinese scholars argue that the assumption that the PLAN’s surface vessels are vulnerable to submarines is incorrect. The PLAN also fields the region’s largest fleet of anti-submarine warfare (ASW) frigates, such as the Type 054A/B along with 76 Type 056 corvettes, which can be used as active emitters, given their relative expendability, although active sonar has its own limitations. China still maintains a relatively limited number of key assets, such as the Y-8Q maritime patrol aircraft (MPA), and the limited evidence of China exercising the coordinated use of ASW assets through synthetic training of MPA crews is showing a growing emphasis on realism. While the PLAN likely has excellent situational awareness in certain areas such as the South China Sea, where it maintains a robust network of sensors, beyond the first island chain it probably faces limitations. These include limited numbers of MPAs, a relative lack of high-endurance helicopters (although this gap is now being filled by the Z-18F) and noisy SSNs, which will be uncompetitive beyond the first island chain. Recent studies examining the difficulties Chinese submariners face on longer deployments also highlight a degree of institutional inexperience. There are, however, offsetting US challenges – namely the fact that, by 2027, the US submarine fleet is likely to reach a nadir in terms of the number of boats at its disposal (with the US Navy likely to field 48 boats at the end of the decade, despite a formal requirement for 66). This force will need to track and contain China’s own SSKs (diesel-electric submarines specialised for anti-submarine duties) and SSNs, in addition to performing offensive functions.

The dynamics and specific characteristics of a Sino-American competition below the waves cannot easily be addressed in detail – the key inputs are too sensitive to approach with open source analysis. However, the determinants of success for each side can more readily be discussed.

Determinants of US Subsea Success

For the US, the employment of SSNs would probably serve several purposes – deep strike, attacks on PLAN SAGs and controlling chokepoints through which the PLA’s SSKs and SSNs might seek transit, and direct attacks on an amphibious force. In addition, SSN operations in the South China Sea might represent a means of diverting Chinese resources. The key constraint that the US will face is that with the exception of deep strike and the elimination of an outer layer of SAGs, many of the missions that SSNs will perform may also require them to transit chokepoints such as the Bashi Channel, over which the PLA could plausibly have early air and naval control, while shallower transit routes will likely be mined by the PLAN’s own submarines. The constraint of geography does not necessarily mean that submarine activity will stop, but it can certainly be slowed if SSNs need to account for minefields and SQ-5 active sonobuoys, laid by both MPAs and Z-18 helicopters. While the ability of the PLAN to detect quiet SSNs is likely to be limited, it should be noted that combat modelling from the Cold War era suggests that in constrained and heavily mined waters the attrition rates of even a force that enjoys a considerable advantage in quietness will be difficult to sustain over time.

Additionally, even successful submarine campaigns have high attrition rates – for example, during the Second World War the US Navy lost 52 of the 248 submarines it deployed to the Pacific, in what is generally regarded as one of history’s most successful submarine campaigns. At least some attrition should be anticipated, irrespective of US advantages, which will lead to a demand for the reallocation of SSNs from elsewhere.

On the other side of the ledger, the US Navy will need to bottle the PLAN’s fleet of SSKs and SSNs within the first island chain to protect its own surface forces in the Pacific from the PLAN’s 48 SSKs and six SSNs. While the Type 093 SSN is still a noisy platform relative to Western and Russian analogues, the PLAN’s SSKs are both quiet and, in the case of the newer Type 039C class, equipped with air-independent propulsion, which increases endurance. China faces constraints, including a requirement for its submarines to transit the same limited number of chokepoints to attack forces beyond the first island chain. However, if the US faces a requirement to track multiple contacts in a crisis escalating to conflict (during which submarines cannot be engaged at chokepoints) this will prove resource intensive. For example, three MPAs are required to maintain a single aircraft on station over a 12-hour period, and once an MPA makes contact with a submarine, tracking it often requires either a surface vessel or a submarine to be devoted to the task over an extended period – spreading resources thin in the early stages of a conflict.

Air Supremacy Over the Taiwan Strait

In the air, the degree to which the US and its allies view air superiority over the Taiwan Strait as a prerequisite for operational success will be a major consideration. In theory, the PLA has a greater requirement for air supremacy than any US-led coalition. Since the PLA is unlikely to achieve a 3:1 numerical advantage on the ground early in an assault, airpower, both fixed wing and helicopters, will be a crucial force multiplier. This is noted in a number of Chinese publications on the subject of amphibious assault, which stress the importance of capabilities such as LHDs, which can launch both helicopters and vertical take-off and landing UAVs to augment fixed-wing aircraft. It is acknowledged, however, that the range of capabilities that can enable beyond-visual-range engagements will mean that control of the air will probably be temporally and spatially bounded. The PLAAF has been steadily improving its direct-attack capabilities over the past two decades. The J-10 series is equipped with the K/JDC01A targeting and laser designator pod to enable the use of precision-guided munitions, and China’s Flanker derivative, the J-16, is equipped with the YINGS-III pod, which is a rough analogue to the USAF’s Sniper Advanced Targeting Pod. In addition, helicopters of the PLAGF, such as the Z-10 and Z-19, can contribute to the suppression of shore-based defences.

All of this depends, however, on the ability of the PLAAF and the PLAN to achieve at least temporary air supremacy over the Taiwan Strait and any likely landing sites. The survival of Taiwan’s air defences as at least a “pop-up” threat, as well as the ability of the US Navy and USAF to mount offensive counter-air operations over the Strait would, in principle, be sufficient to deny the PLAAF the freedom of action needed to deliver a breakthrough, much in the way that Ukraine was able to deny the VKS (Russian Aerospace Forces) air superiority for the first two years of the war in Ukraine. This depends, however, on the ability of the US Navy and USAF to sustain a tempo of activity and level of attrition necessary to give the People’s Liberation Army Naval Air Force (PLANAF) and the PLAAF an incentive to limit their operations over the Strait, while themselves being forced to operate at greater ranges due to the land-based missile threat. In 2015, research conducted by RAND suggested that the likelihood of the US achieving either air superiority or a victory sufficient to drive the PLAAF from the Taiwan Strait would be constrained if the distance from which platforms would need to operate increased, as it necessarily would if the tempo of US air sorties was lowered by the requirement to keep aircraft carriers out of range of the DF-17 and DF-21D. This in turn might lead to the inference that an offensive counter-air campaign cannot be effective unless the sortie rates of the PLAAF and the PLANAF are also lowered, necessitating strikes on the Chinese mainland and an enabling suppression of enemy air defences (SEAD) effort. For example, capabilities such as cruise missile submarines (SSGNs) equipped with the US Navy’s new hypersonic glide vehicle might be used to create gaps in the Chinese IADS, which aircraft could temporarily exploit, provided that they receive real-time targeting data from offboard sources.

Air Defence

Even if pervasive ISR can be delivered, the types of missiles likely to penetrate an IADS without robust enablement (such as the US hypersonic Dark Eagle) are likely to be scarce, relative to their targets. Limited SEAD using expensive munitions such as the Dark Eagle (which will be launched from Virginia-class SSGNs if cued by offboard sources) might open gaps in an IADS to enable the use of slower long-range standoff capabilities such as the Tomahawk Land Attack Missile or strategic bombers to suppress airbases. While disrupting air activity is likely to be important, any effort to achieve this on a consistent basis would require US aircraft to sortie even further than they would need to in the context of offensive/defensive counter-air (OCA/DCA) missions over Taiwan, as some elements of an air defence network would be inland. Moreover, the amount of payload required to cause irreparable damage to an airbase is considerable. For example, Shayrat Airbase in Homs, Syria was made functional again in just a day despite being hit with 58 cruise missiles. In this context, a SEAD and strike campaign to disrupt the 32 PLAAF airbases within 800 km of Taiwan would be functionally indistinguishable from AirSea Battle as originally envisioned, and thus as difficult to resource. An air and naval force that can conduct such a campaign can achieve the much more modest goal of OCA/DCA over Taiwan (which would probably condemn an invasion to failure) with relative ease, making strikes inland at large scale superfluous, given how critical air superiority is to the PLA.

Assessments regarding the tempo of activity required to achieve a successful DCA effort can be contested if the object of the effort is presumed to be air denial. First, the figures that were deemed to determine success in previous analysis were based on air superiority, not denial per se, and thus set a high bar for the levels of attrition the US Navy and USAF need to inflict (and thus the number of sorties required). Successful air-denial campaigns such as North Vietnam’s defence of Hanoi during the Vietnam War and the Egyptian defence during the early days of the Yom Kippur War in 1973 inflicted considerably less attrition – roughly 4% per sortie in each case – before air operations were either temporarily deemed prohibitively difficult or had to be enabled in ways that reduced the overall tempo of activity to the point of operational ineffectiveness.

Second, the impact of Taiwan’s own SAM network, comprised of systems such as Patriot and the TK-III, must also be considered. This network could certainly be crippled early in a conflict, particularly if its constituent sensors emitted to defend high-value targets against ballistic missiles, but elements could also be conserved to present a pop-up threat to aircraft near likely landing sites. The US Navy’s own SAGs would also likely be able to inflict attrition on PLA aircraft from beyond the first island chain. Although the effective range of SAM systems such as the SM-2 and SM-6 will be constrained by factors such as target altitude, they are likely to inflict attrition on PLA fast air, especially as the latter moves beyond the first island chain to engage tankers and AWACS.

An additional reason for a focus on denial over the Taiwan Strait is that the ISR required to sustain attacks on the mainland cannot be assured, although steps are being taken to make it more resilient.

The US operates a diverse list of ISR capabilities in the air and in space. In the air, both autonomous systems and crewed aircraft, such as the U-2, can provide rapidly deployable reconnaissance. In 2019, the USAF was reported to have “425 manned and unmanned aircraft of 14 different types” at its disposal for data collection, although not all of these will necessarily be survivable in a hostile IADS.

The vast ISR infrastructures in space are constantly being diversified to meet the new realities of the space age – the emergence of commercial actors and the continuous threat against space systems. The US National Reconnaissance Office is responsible for spy satellites, and is already working on a more proliferated infrastructure, which may hint at the placement of satellites in different orbits to cover different purposes. While satellites in higher orbits (such as Medium Earth Orbit, from 2,000 km and above) can cover wider regions, satellites in lower orbits (low earth orbit (LEO), below 2,000 km) can provide more detailed and perhaps more tactically relevant information.

However, the availability of persistent ISR against elusive targets cannot be assumed. US dependence on space assets and pervasive ISR more broadly presents a potential weakness. The PLA is growing increasingly reliant on its own space weapons, including in the targeting realm. Moreover, many of the large, fixed-wing ISR assets on which the US’s way of war has depended thus far will not be survivable in the Pacific.

Space Warfare Aspects

Space systems – the satellite in orbit, the ground station on Earth and the signals in between – are all vulnerable to attack. In terms of disrupting ISR assets, satellites could be interfered with temporarily or permanently through laser dazzling or a cyber attack. At the extreme end of the spectrum, the satellite could be permanently damaged through a high-altitude nuclear explosion or a kinetic kill through either a co-orbital weapon or a direct-ascent anti-satellite missile. China’s capabilities in that realm are not entirely clear, partly because they have not yet been demonstrated in a war. According to Chinese reports, however, a successful laser blinding test of a Chinese satellite at 600 km altitude was carried out as early as 2005. It is unclear whether this technology has since been used against non-Chinese assets. China also has the capability to kinetically destroy satellites – at least in LEO. Permanent interference with systems – either through a close proximity manoeuvre, a kinetic kill or a nuclear detonation, is theoretically possible, and in the case of China, practically possible as well, although these operations have mixed tactical utility. As such, a complete denial of ISR in the Pacific should not be assumed. Even so, the pervasive ISR needed to track transport erector launchers (TELs), which can move at relatively short notice (typically 15 minutes after a launch), will be difficult to achieve.

The proliferation of commercial assets might add some resilience to surveillance networks. The US Space Force has made it clear that it wants to work more closely with commercial providers. Even if the PLA managed to destroy several sovereign ISR satellites, the number of missiles required would create so much debris that Chinese space assets in that orbit would most likely be adversely affected as well. For example, in 2024 the US Space Force published a commercial space strategy outlining how collaboration with the commercial space sector was going to be integrated in the future. The Space Force had already begun experimenting with a so-called “Space Tactical Layer”, which would integrate commercial satellite images “to improve battlespace awareness and expand its beyond-line-of-sight targeting capability”.

Therefore, while the challenge of counter-space capabilities does not imply a complete denial of information, the level of low-latency ISR required to sustain a full-scale strike campaign against elusive targets is unlikely to be available. Strikes on the Chinese mainland will likely be a component of any US campaign, but their scale and tempo will probably be limited.

Summary

If the more modest aim of denying the PLAN and the PLAAF freedom of the skies is the primary operational aim, many of the challenges associated with tracking elusive targets inland and projecting power are less salient. Moreover, the tyranny of distance is less relevant if the US Navy and USAF are primarily operating either over the Taiwan Strait or as carriers of standoff missiles. To be clear, this report is not arguing that the US will necessarily achieve with ease the tempo of activity required to deny the PLA air superiority, merely that attacks on the mainland will not be determinative of their ability to do so.

II. Implications for Europe

This chapter focuses on how the resource demands placed on the US in a Taiwan Strait contingency might affect conventional deterrence in Europe. Per the NATO Strategic Concept and the DDA family of plans, the Alliance must prepare for war at large scale on its eastern flank. A low-probability, high-impact contingency, which might focus contingency planning, would be a full-scale Russian invasion of the Baltic states, which has been discussed in some detail. Moreover, while some might challenge the realism of the Baltic case, it is still useful as a means of stress-testing European capabilities and baselining requirements for high-end warfighting in the event of a commitment of US capabilities elsewhere.

This chapter does not seek to provide an exhaustive overview of every aspect of a potential clash between NATO and Russia, nor their specific dynamics. These details are highly contingent. Rather, its purpose is to examine how chosen US and Chinese strategies in the Indo-Pacific might have an impact upon specific sub-components of the aggregate military balance in Europe.

The discussion covers several areas. First, it analyses the impact of an Indo-Pacific campaign on the capacity of NATO to support a SEAD campaign in Europe. This is a clear priority, given that airpower represents the Alliance’s most viable means of offsetting the challenge of Russian combat mass on the ground. With more than 2,000 fourth-generation combat aircraft across the Alliance (excluding the US), European NATO has, in principle, the capacity to inflict a level of attrition comparable to that achieved in 1991 in Iraq, where allied airpower inflicted 24% attrition on the Republican Guard before it made contact with coalition ground forces. This depends, however, on the ability to attrit a dense multilayered Russian IADS built to preclude precisely this eventuality, and the success or failure of a campaign in Europe will depend in no small measure on whether this is achieved.

Second, the availability of air and missile defences is examined, for several reasons. One reason is that Russian military scholarship has over the past decades placed a considerable emphasis on “non-contact warfare” – the ability to see and strike in depth. Russia views long-range strike as vital, both to its efforts to limit the impact of NATO airpower through suppression on the ground and to its ability to force war termination on favourable terms by targeting critical national infrastructure (CNI). Moreover, the threat of ballistic missiles at key chokepoints, such as railheads and bridges, will be a limiting factor for the rapid deployment of ground forces, as well as for the tempo of air activity.

Russia’s submarine fleet will play several functions in any conflict, acting not only as part of any strike campaign, with its new Yasen-class SSGNs, but also as a threat to allied sea lines of communication and CNI. The ability of NATO to contain the Northern Fleet is thus the third priority area on which this chapter focuses.

Finally, the chapter examines the impact of an Indo-Pacific contingency on the land component of Supreme Allied Commander Europe’s (SACEUR) forces within the NATO area of responsibility, given the centrality of combat on the ground to deterring Russia, and since the land domain may be an area where trade-offs and resource constraints can most easily be avoided.

Potential Differences Between SEAD Across Regions

The degree to which SEAD in each region is dependent on the same sets of enablers is, fundamentally, a function of the chosen US approach in the Indo-Pacific. This stems from the fact that, in the early stages of a conflict over Taiwan, the IADS protecting an invasion force will be primarily comprised of maritime theatre air-defence platforms such as the Type 055 and Type 052D, as well as aircraft. Although the ability of the PLAN and the PLAAF to form a single JEZ is disputed, it is reasonable to assume that the PLA will accomplish similar effects to the Russian army’s SAM systems and the aircraft of the VKS in Ukraine. While China fields an increasingly robust array of ground-based SAM systems, including the indigenous HQ-9 and the Russian S-400, the degree to which these systems could provide coverage to a PLAN force from the Chinese mainland is likely to be limited, for reasons discussed in Chapter I and briefly restated here.

Against low-flying targets such as cruise missiles, the radar horizon is still a factor that prevents missiles from being used at their theoretical maximum ranges. While capabilities such as AWACS can be used to cue ground-based SAM systems, the difficulties of doing so have been outlined in Chapter I. Additionally, these systems are large, difficult to hide and at the time of writing limited in number and likely to be targets for any US OCA campaign, as well as for strike assets built specifically to penetrate a Chinese IADS from standoff distances.

This in turn means that SEAD in the Taiwan Strait is not primarily a function of finding and engaging elusive targets such as TELs. Rather, SEAD is largely synonymous with anti-surface warfare and OCA. If the picket of destroyers and cruisers protecting an invasion force suffers substantial losses and if PLA aircraft, including AWACS, cannot freely operate over the Strait, the amphibious vessels on which an invasion defends are much less defensible, with the probability of successful cruise missile strikes against them rising to 0.4–0.8. The challenge is not that targets are elusive, but rather that they are exceedingly well defended. Chinese analysts’ assumptions, for example, are that sinking a modern destroyer requires a combination of six ASCMs flying at different speeds and altitudes, as well as an anti-ship ballistic missile. Notably, these assessments are often based on overwhelming hard-kill systems and typically do not account for the fact that vessels have robust soft-kill mechanisms, including jamming and deployable digital radio frequency memory decoys.

By contrast, SEAD in the European context is primarily a function of the ability to suppress or destroy a layered network of elusive and mobile ground-based SAM systems. The outer layer of this network comprises shorter-range systems such as the SA-11 and the SA-15, with longer-range systems such as the SA-20/23 (S-300-PMU-2/S-300VM) and the SA-21 (S-400) positioned to the rear. Longer-range systems, by virtue of being able to emit, allow shorter-range systems to engage without turning on their own radar. Furthermore, systems such as the SA-22 Pantsir can act as shorter-range point defences against incoming munitions and UAVs.

This description, while a simplification, captures an inherent challenge of contending with the Russian IADS. To safely and consistently engage long-range SAM systems in rear areas, a larger number of elusive targets that form the outer layer of the network must first be destroyed. However, the task of attacking those short- and medium-range systems at the front edge of the IADS is greatly complicated by the presence of the long-range systems that enable short-range systems to engage without emitting. The long-range ISR platforms that enable the mapping and targeting of SAM systems in an IADS, such as the E-3 AWACS and E-8 JSTARS (Joint Surveillance Target Attack Radar System), are at risk of being engaged at extended distances by SAM systems such as the S-400. While missiles such as the 40N6 cannot be consistently cued at their maximum ranges (400 km) against low-flying aircraft (although they can intermittently conduct engagements at very long ranges), they can effectively engage larger targets at the extent of their range. Moreover, anti-radiation missiles designed for SEAD, such as the AGM-88 HARM, are both vulnerable to attrition by point defences and less effective when their target radars do not have to emit because they are receiving external cueing. As a consequence, they can be expended in unsustainable numbers. In the 1999 air war over Kosovo, for example, the Alliance expended 815 AGM-88 HARMs against a much weaker opponent. The resulting requirement is for munitions with both the low-radar cross-section needed to penetrate an IADS and the sophisticated seekers (typically either dual-mode or millimetric wave radar) needed to engage mobile targets when they have stopped emitting. Munitions in this category include the AARGM-ER and the SPEAR 3.

Largely, then, SEAD in the Indo-Pacific need not draw on the same munitions and enablers as SEAD/DEAD in Europe. The latter will depend on allied fleets of fifth-generation aircraft (which are the only air capability that can be employed at acceptable risk against an IADS) being equipped with sufficient stocks of munitions such as the ARRGM-ER, built to track elusive TEL and radar (TELAR) and mobile radar systems. These munitions have limited utility against SAGs, given their smaller payloads and the comparatively short distances from which they must be launched. While the functionality of munitions such as the AARGM-ER against ships has in theory been proven, the payload of the missile does not correspond to those needed to either inflict a mission kill on or sink a major surface combatant. Top attack against a vessel’s radar might be considered, but even a low-radar cross-section missile is vulnerable to being engaged by the point defence systems on a ship if it travels relatively high to engage a radar. Moreover, the launch ranges of the AARGM-ER would require aircraft carrying them to fly in areas where they are not only at risk from destroyers themselves but are also likely to engage in air-to-air combat with the PLAN and the PLAAF. In this context, the AARGM-ER will compete for rail space with air-to-air interceptors.

The requirement to support two SEAD campaigns need not necessarily impose an unacceptable munition strain on the US if it supports allies in both Europe and the Indo-Pacific. However, this does not take into account the several other aspects of a credible SEAD capability currently lacking in European air forces, including the need to prioritise training for SEAD missions over other competencies. A purely materiel-focused deduction that could be drawn, however, is that the various gaps in European SEAD capability platforms and training represent a more acute issue than munitions, given the inherent differences in SEAD across the two theatres.

There are several caveats worth noting. First, the above analysis is entirely premised on the assumption that sea denial, rather than overmatch, is the chosen US approach. In this context, the determinant of success is ultimately the ability to set the conditions for sinking enough amphibious vessels to make an invasion unviable, not to comprehensively defeat the PLA to force China’s leaders to negotiate. If it is deemed that war termination requires the ability to escalate against the Chinese mainland, for example because the PLA responds to failure by shifting to a blockade or a strategic bombardment, the same munitions and aircraft needed for SEAD in Europe will also be required in the Indo-Pacific. However, for the reasons outlined in Chapter I, it is deemed unlikely that this will be a viable option.

Second, there will probably be ground-based SAM systems set up on islands such as the Pescadores if the PLA takes them, meaning that the suppression of systems such as the HQ-9 and the HQ-16 will not be entirely irrelevant.

A maritime SEAD campaign will draw on stocks of other capabilities such as ASCMs and submarines, among other things, all of which will be important in Europe. Although limited in size and complexity, Russian surface combatants can pose a threat at operational ranges from positions near their bastions, such as Kaliningrad, using 3M-14 Kalibr cruise missiles. While unlikely to be decisive, this could well result in a political demand to engage Russian surface combatants within well-defended bastions from which they launch cruise missiles that will draw on limited stocks of ASCMs, as well as capabilities such as SSKs and SSNs. While exact stocks of anti-ship missiles held by European states are unknown, several European navies have temporarily plugged the gap in this capability. Interestingly, one of the most pressing gaps that a US SEAD/DEAD campaign in the Pacific might create in Europe is a gap in surface lethality in the maritime domain.

IAMD: A Capacity Challenge Across the Board

IAMD represents a capability that is especially fungible and likely to be in high demand across the Indo-Pacific and the Euro-Atlantic. Russian and Chinese concepts for future warfare envision long-range precision strike playing a prominent role, although Russia tends to accord a more prominent role to countervalue targeting than does China. Illustrative of the prominence of deep strike in Russian concepts of operations is the fact that Russia had by 2023 expended over 5,000 cruise and ballistic missiles in the war in Ukraine.

In Europe, Russia faces a larger target set with considerably more strategic depth. Unlike the Indo-Pacific, the European theatre has far more airfields from which NATO’s jets or aircraft can operate, making near-complete airbase suppression, as contemplated by the PLA in the Pacific, nearly impossible for Russia to achieve. Within 500 km of Russian-held territory, however, the threat is more acute, and will require the use of airfields in the west of SACEUR’s area of responsibility and thus increase the Alliance’s reliance on tanker aircraft. There are also individual points of failure within allied air forces. For example, Automatic Logistics Information System terminals, which enable the mission planning and logistical support on which the F-35 depends, are held at a limited number of airbases, many of which have undergone public and expensive conversions to host the F-35. Moreover, Russia’s doctrinal commitment to striking CNI as a means of forcing de-escalation would probably impose competition for resources between NATO as an alliance and those nations that must ultimately make voluntary contributions to its air defences. The logic of Alliance-level planning would incentivise the protection of military assets, which in turn would enable the prosecution of an effective war effort. But national political imperatives may dictate otherwise, creating a risk of competition for scarce IAMD assets. In the close battle, Russia can generate a dense multi-tiered threat comprising short-range ballistic missiles such as the 9M723, cruise missiles, loitering munitions and fixed-wing aircraft launching unguided glide bombs such as the FAB-500.

While the air threat is a challenge across both theatres, there are differences between the IAMD requirements that bear consideration. Russia does not field a credible intermediate-range ballistic missile (IRBM), having cancelled the RS-26 in 2017, and it would struggle to increase IRBM production in less than a decade, given its production rates for more mature SRBMs. As such, beyond 500 km the Russian threat is effectively a cruise missile threat. This means that certain interceptor types, including exoatmospheric and high endoatmospheric interceptors, such as the SM-3IIA and systems such as THAAD (Terminal High Altitude Area Defense), are far more relevant to the Indo-Pacific than they are to Europe – although, as will be discussed, longer-range ballistic missile defence (BMD) systems will be of use in Europe to a degree.

The primary BMD challenge facing Europe is SRBMs. Although the KH-47M2 Kinzhal can be used at operational depth, doing so risks the bomber or fighter aircraft carrying it. Russia is developing IRBMs, but the development cycle for missiles typically exceeds a decade, and further time elapses before they are fielded in numbers. In the first year of the war in Ukraine, Russia fired 700 Iskander SRBMs (135 in the first month), and in 2023 appeared to be producing cruise and ballistic missiles at a rate of 40 per month. The 9M723, which can dispense six radar decoys in its terminal phase, is a challenging SRBM to intercept, and the task is likely to require millimetric wave seekers such as the Ka-band seeker of the PAC-3 or the Aster-30 Block 1NT. This will create a considerable demand for hit-to-kill interceptors, although this demand will be bounded by the duration of a SEAD campaign, after which missile launchers can be more readily attacked before missile launch.

Expenditure Rates

Expenditure rates on interceptors are dependent on several factors, including shot doctrine and the rate at which launchers can be engaged before launch by aircraft and ground-based weapons, which is likely to increase as the IADS protecting them is diminished. For example, a two-shot doctrine (independently firing two interceptors for any given target) and a “shoot–look–shoot” doctrine, in which a second interceptor is only employed if the first fails, see 2 and 1.1 interceptors fired per target respectively to achieve a 0.99 probability of kill (Pk), while other studies suggest considerably more, with up to eight interceptors needed for certainty of kill with an SSPK of 0.5 (although this assumes a low SSPK, and very demanding criteria for success). Applied to the European theatre, more modest assumptions could still mean a requirement for anywhere between 770 and 1,400 hit-to-kill interceptors in the first month of a conflict if Russia expends Iskander at the rate it has in Ukraine. While the US current production rate for PAC-3 MSE interceptors is 500 per year, with an aspiration for 870, this capacity will be drawn on by a number of commitments, including the ongoing war in Ukraine, foreign military sales and the Indo-Pacific. In 2022, the US entire stock of PAC-3 MSE was 1,600 interceptors. However, over time the effects of a successful SEAD campaign should make launchers considerably vulnerable to pre-launch interception and would, moreover, undercut the ground campaign that ballistic missiles support. There is no automatic reason to assume a SEAD campaign will succeed, of course, but if it does not, the problem facing the Alliance is wider than the missile threat.

There is considerable risk of capacity strains with respect to hit-to-kill interceptors. There are, however, differences between the European and Indo-Pacific theatres in this respect. Longer-range interceptors such as the SM-2 and the Aster-30 Block1NT can be relevant in each context, but to very different degrees. In Europe, there are no IRBM or medium-range ballistic missile (MRBM) threats against which longer-range interceptors will be prerequisites. What long-range hit-to-kill interceptors could provide, however, is a means of considerably reducing the point defence burden. Even a marginally resourced first layer against SRBMs can considerably reduce the burden on point defences. This is partly a function of the fact that early interception can prevent the deployment of countermeasures and partly the fact that shot doctrines, which conserve interceptors, are more viable in a layered defensive system. As a notional example, the requirement for shorter-range defences can be reduced by 75% from the ability to engage half the incoming targets with an outer defensive layer, at a cost which is in aggregate lower than a single-layer system. What this means in practice is that the rate of expenditure of a European IAMD network against ballistic targets could be improved substantially by a relatively limited number of longer-range hit-to-kill interceptors, even if these interceptors had less than the 0.8 Pk typically required of air-defence systems. In the Pacific, capabilities such as the SM-3IIA will be a primary mode of defence against medium- and intermediate-range targets, against which point defences will have more constrained utility. The vessels that field them will also defend themselves against MRBMs, such as the DF-21D, over the course of a campaign. In effect, the need for a first layer of longer-range hit-to-kill interceptors in Europe may be more modest than in the Pacific, insofar as its role is reducing an otherwise unmanageable strain on shorter-range interceptors.

Interceptor Platforms

These interceptors are often (but not always) held on maritime platforms, and the availability of such an outer layer would require destroyers and frigates to be equipped with requisite interceptors and postured forward in areas such as the Baltic Sea, at some risk to themselves. This also limits the reach of an outer air-defence layer away from coastal areas. Moreover, many of the destroyers that carry longer-range hit-to-kill interceptors are US vessels, such as the Arleigh Burke class. Several European navies, including the Royal Navy, Italy’s Marina Militare and France’s Marine Nationale, are investing in longer-range hit-to-kill systems such as the Aster-30 Block1NT, but the question of how much capacity will exist by 2027 is still open. In effect, capacity gaps in European tactical BMD can be filled without the procurement of a potentially unrealisable magazine of interceptors, but only if the likely absence of US Aegis destroyers and their interceptors can be offset.

Alternatively, European states will need to find ways to deliver the number of interceptors required to achieve point defence against short-range ballistic targets. In principle, the initiative by Germany, Romania, the Netherlands and Spain to procure 1,000 PAC-2 GEM-T interceptors (which are not hit to kill but can be used against ballistic targets) and Germany’s procurement of up to 600 PAC-3 MSE interceptors would, if realised, meet the requirement against an initial ballistic missile salvo comparable to that seen in Ukraine (although only the PAC-3 is a hit-to-kill interceptor optimised for BMD). However, this would depend on sensors supporting tactical BMD having enough range to support a shoot–look–shoot approach (a challenge, since no European NATO member fields longer-range BMD radar such as the AN-TPY-2, which would allow lower-tier defences to focus on likely vectors of attack, enabling a more efficient shot doctrine).

In contrast to BMD interceptors, which may be required to differing degrees (depending on their range), blast fragmentation interceptors are likely to be in considerably higher demand in both theatres. Both Russia and China maintain large cruise missile arsenals and, in the case of Russia, cruise missiles have been augmented with cheaper analogues, such as the Shahed-136, which are less capable but must still be engaged. Moreover, blast fragmentation interceptors are also expended against uncrewed aerial systems and loitering munitions. Interceptors such as the AIM-120 AMRAAM, which are common to both aircraft and ground-based air defence systems such as NASAMs, are likely to see heavy demands from both the Pacific and the Euro-Atlantic. Any US air activity in the Indo-Pacific, irrespective of whether it aims for the more modest goal of air denial, which this report argues to be optimal, or for more expansive aims, will necessarily use considerable numbers of blast fragmentation interceptors. For European states, aircraft – and in particular those aircraft that cannot be immediately committed to ground support missions – will be a crucial component of any air defence effort against cruise missiles and one-way attack munitions. In addition, air-to-air combat against the VKS is likely to be a feature of any European conflict, even if the VKS might be expected to operate in a conservative way within the safety of its own IADS. It then follows that, particularly where European systems rely on blast fragmentation interceptors made in the US, these missiles may become a scarce asset, in demand across both the European and Indo-Pacific theatres.

Counter-rocket, artillery and mortar (C-RAM) systems and V-SHORAD (very short-range air defence) systems will be in demand to differing degrees in both theatres. Given the likely importance of vertical lift to the PLA’s efforts to generate superior firepower over any beach-head, as well as the role of platforms such as the Ka-52 in supporting Russian efforts to contain allied armour, MANPADS such as Stinger are likely to be in relatively high demand in both theatres. In Ukraine, for example, the US Department of Defense has donated a third of its arsenal of Stinger missiles. The PLA, for its part, fields 270 Z-10 and Z-19 attack helicopters. The Z-10s are a rough (albeit lightly armoured) analogue to the US Apache and are equipped with 16 anti-tank guided missiles. Keeping these systems at bay without employing SAMs intended for more expensive targets will be of considerable importance. Unlike heavier systems, MANPADS can probably be moved to Taiwan rapidly and at scale in a crisis, as was the case in Ukraine. There are a number of European producers of MANPADS, and reliance on US capabilities that may be moved to Taiwan would not be a bottleneck in itself. However, the ability to scale production and secure critical inputs would require both industrial capacity and the ability to ensure that different Western producers are not competing for the same components.

C-RAM has, historically, been more important in the context of Europe than in Asia, given the centrality of fires to the Russian way of war – which saw, for example, the Russian armed forces expend up to 38,000 artillery rounds a day in the second year of the war in Ukraine. By contrast, the relatively limited fires capabilities of the PLA’s amphibious assault forces would likely see them relying on air and naval support to generate firepower. A PLAGF combined arms brigade, for example, contains a single artillery battalion, compared with the three in a Russian Motor Rifle Brigade. The three PLA group armies across Taiwan also field an artillery brigade each, equipped with 300-mm PHL-03 and PHC-191 MLRS systems that can target Taiwan’s west coast from the mainland. Even so, the sheer weight of land-based artillery fire in the initial period of an invasion of Taiwan is likely to be dwarfed by the volumes of fire expended in the European theatre. Certainly, some C-RAM systems, such as Phalanx, have utility as a means of defending installations against UAVs, but in general UAVs can be engaged by cheaper means, such as anti-aircraft artillery fire. As such, mobile and survivable C-RAM remains more relevant to the European theatre than to the Indo-Pacific.

ASW: A Major Capability Gap

The allied approach to ASW in Europe is to a substantial degree dependent on US assets. First, the tracking of a single contact typically requires the coordination of several systems, including MPAs, frigates and SSNs which must, respectively, localise and then tail a contact. It typically takes three MPAs to maintain one MPA on station at any given time over a 12-hour period. Currently, European MPA fleets are relatively small – at the time of writing, the UK fields five P-8 Poseidon aircraft and Norway a further eight, while France and Germany field 11 upgraded Atlantique aircraft and P-8As respectively. Portugal also fields a fleet of older P-3 Orion aircraft. This is a limited but not completely insufficient number of platforms for manning a chokepoint such as the Greenland–Iceland–UK (GIUK) Gap, particularly in terms of the relative overmatch that the Alliance enjoys in theatres such as the Baltic Sea, where Russia currently operates a very limited submarine force, comprising a single Kilo class (although SSKs from other fleets could be moved to the Baltic in a crisis). A more significant issue will be the availability of key systems stocks such as multi-static sonobuoys, given the substantial dependence on US systems. A barrier in the GIUK Gap, for example, would need to be seeded with 15,000 DIFAR and DICASS sonobuoys, which would be reseeded every eight hours (although newer MAC sonobuoys have greater coverage, reducing the number required by half).

Once a contact is made by, for example, an MPA, a submarine is typically tracked over long distances by another SSN. The limited size of allied SSN fleets will make this a challenge in the absence of US assets, which is likely if the US Navy faces a trough in submarine capacity in the 2030s. While it enjoys considerable advantages in comparison with the PLAN’s much noisier nuclear submarines, the US Navy’s SSN will not necessarily have major advantages over quieter SSKs, such as the Type 039C, in littoral waters of areas such as the South China Sea, where advantages such as endurance are of less significance. It is likely that clearing the South China Sea of Chinese submarines and surface vessels will be crucial to ensuring that US surface assets operating in the western Pacific do not do so at unacceptable risk from PLAN platforms operating on interior lines. In this instance, the US Navy could opt to simply cover chokepoints such as the Bashi Channel and the island of Mindanao and bottle in Chinese assets (a less resource-intensive task). But if the PLAAF seizes local air superiority sufficient to allow China’s own MPAs to operate over these chokepoints (at least for a time), this will probably involve both risks and losses. It should be noted that even historically successful submarine campaigns have involved high loss rates. For example, the US Navy lost 20% of its submarine fleet in the Pacific theatre during the Second World War, despite enjoying considerable advantages over the Imperial Japanese Navy. It is thus not inconceivable that the Pacific, which since 2015 has drawn 60% of the US’s SSNs, will demand an even larger part of the SSN force in a conflict. The position of the JMSDF, which operates a fleet of 10 quiet Soryu-class SSKs (among other vessels), will be an important factor in determining precisely how acute the demand for US submarines is in the Pacific.

In Europe, the Russian Northern Fleet currently possesses 14 SSNs and SSGNs, of which a relatively large number can be surged in a conflict. By 2030, Russia aspires to field six Yasen-class submarines across its Northern and Pacific fleets. This increase, if achieved, will potentially be offset by the retirement of older Victor III- and Sierra-class submarines still in service, and will not necessarily represent a quantitative increase in fleet capacity. Qualitatively, however, this would entail a step change in the threat facing NATO, given that the Yasen is comparable in quietness to newer Western submarines and capable of launching supersonic and hypersonic missiles such as the 3M22 Zircon.

Potential Shortfalls

Assuming a partial or complete absence of US capacity, NATO would probably face considerable shortfalls in several areas, including stockpiles to enable MPA operations and available SSNs to tail Russian contacts. Collectively, the UK and France field 16 SSNs, which is more than Russia’s Northern Fleet, but a focus on persistent deployment rather than surge capacity means that the part of this force that can be made available at short notice is more limited than for a comparably sized Russian force. This could change, particularly because Russia appears intent on maintaining persistent deployments of SSGNs in the Western hemisphere (which will absorb at least four Yasen-class SSNs to keep one on station at any time and have an impact on readiness). However, not maintaining surge capacity would represent a break with Russian and Soviet practice, and some effort to do so should be assumed.

Western SSNs are required for additional functions such as deep strike and forward operations at sea in otherwise denied maritime spaces. In the absence of a significant number of US SSNs in theatre, then, the requirement of tailing the part of its SSN fleet that Russia does choose to surge in a crisis could create a shortfall in available SSNs, which could impact both strike operations at depth and ASW operations. Moreover, it is not clear that there will be enough SSNs to meet the task of tailing alone.

This latter challenge can be offset in several ways. SSNs do not have to be tailed by other SSNs, and both surface vessels and SSKs can also play this role. The former, however, operate at considerable risk against SSGNs, given their own often relatively limited air defences, while the latter have limited endurance and speed relative to their quarry. Once NATO is covering an ASW barrier in the GIUK Gap this may matter less – this barrier is likely to be covered by a large number of vessels, as many European states field ASW frigates. However, in a crisis leading to conflict before a Maritime Component Command can be stood up, the difficulty of tailing contacts without engaging them could dislocate naval forces in the theatre. This, in turn, could create the space for other maritime threats, such as the use of special-purpose submarines such as the X-Ray and the Paltus to disrupt critical maritime infrastructure.

Ultimately, Russian threats in the maritime domain are ancillary to those on land. The Russian navy exists to support the army, and if European capability gaps in other areas are filled, the maritime domain may have less significance. Nonetheless, the Alliance’s ability to contain subsurface threats will partially determine Russian assessments of the aggregate balance of forces, and gaps in this area will prove particularly acute.

The Land Component: The Capabilities are Available, But Not the Enablers

In principle, land power should be the most non-fungible US strategic capability in a two-war scenario. While there is certainly a land component to any conceivable Indo-Pacific conflict, the conditions for success or failure are likely to be set at sea and in the air. Since any Chinese approach to Taiwan must presume air and naval superiority, given the low likelihood of the PLA achieving local preponderance at its beach-heads, if Chinese forces do land on Taiwan and achieve a breakout it will be because they were enabled by these two factors. If this is the case, there is little evidence that additional support to a Taiwan ground component could be flowed into the island. Equally, if the conditions for substantial US ground forces to flow into Taiwan can be set in the air and at sea, this would be synonymous with the failure of a Chinese invasion in any case, as any disembarked force would necessarily be cut off from the mainland.

This is not because land forces are irrelevant in a Taiwan contingency. Considerable historical data suggests that a well-entrenched land component can hold an invading force in an island assault under conditions of numerical inferiority and inferiority in the air and at sea, and that attackers often require a more than 3:1 preponderance in land forces. On Okinawa in April 1945, for example, entrenched Japanese forces held for three months against a US force that outnumbered them 5:1, with the US Tenth Army expending 2.4 million shells in the battle. It can thus certainly be argued that the ability of the Taiwan land component to both contest an initial beach-head and protract a conflict sets the conditions for effective denial in the air and at sea by buying time for US forces. Many of the capabilities relevant to a land war in Europe, such as guided MLRS, V-SHORAD and tube artillery, would certainly be relevant in this context.

However, the success of any land battle would be largely predicated on the assets already in Taiwan when a conflict broke out. Assuming the PLAN and the PLAAF are able to achieve a level of air superiority sufficient to enable an outnumbered assault force to break out of its beach-heads (the only context in which a protracted land battle can occur), this would preclude any additional land forces from being surged into the theatre, as some have argued they might be. For example, the US Navy can, in principle, support the insertion of heavy armour into Taiwan with its ship-to-shore connector, but with a 25-nautical-mile radius, doing so under conditions of adversary air superiority would entail amphibious vessels taking unacceptable levels of risk for the insertion of relatively small amounts of armour. Access to ports, which can be utilised by strategic sealift assets, would also be unlikely under these circumstances. It might be argued that, in due course, a successful US effort to roll back the PLAN and the PLAAF could enable land forces to be flowed into pockets of the theatre still held by Taiwan’s forces, to enable the PLAGF to be progressively rolled back on the island – in a manner comparable to the US Army and Republic of Korea army’s defence and breakout from the Pusan Perimeter in September 1940. However, if the PLA does secure a level of air superiority sufficient to prevent its forces from being stopped either at its beach-heads or in the littoral and to allow the subsequent seizure of a port to allow the flow of non-amphibious units, there will be little time for reinforcement. In amphibious assaults over the course of the last century, when a force that did not enjoy numerical preponderance at the outset of the assault succeeded, it typicall did so in less than a month. This broadly reflects the fact that if the numerically inferior force could not be defeated at its beach-heads, it was enabled to succeed by a level of air and naval superiority that caused the defence to collapse rapidly. The only exception to this was the Battle of Iwo Jima, which lasted for a month but in which air and naval power did not play a decisive role in routing the defence. Even if Chinese forces took a month to seize a major Taiwan seaport to enable the flow of follow-on forces, it would probably be longer than this before the US could safely surge land forces into the theatre. In effect, then, if the PLA’s air superiority is sufficient to prevent a numerically inferior force from being beaten on the beaches, a Taiwan defence will collapse before the conditions for reinforcements to enter the theatre can be set.

This is not to suggest that the PLA will necessarily secure the level of air and sea superiority needed to enable a successful invasion. Rather, the argument is that the crux of any defence of Taiwan will be denying it this superiority. If this is achieved, it is likely that Taiwan’s forces can mount a successful forward defence of likely landing sites on the island, making a protracted defence and the subsequent flow of US forces superfluous. If not, the battle will likely end before either of these things can be considered.

This does, in principle, mean that assets such as MLRS equipped with cluster munitions and land-centric capabilities such as heavy armour would be likely to be free for the European theatre, where they have far greater relevance against a primarily ground-based Russian threat, in tandem with the forces already under V Corps in Poland. The scope and scale of this threat will depend on a number of factors, among which are the question of whether Russia can free its forces from their existing commitments in Ukraine, and whether the Russian military can achieve its aspiration to stand up two new military districts and 14 new divisions, in accordance with the plans laid out by former defence minister Sergei Shoigu. This will prove challenging, as Russia has expended much of its stock of Soviet-era equipment and has, since 2008, shuttered many of the training academies for its officer corps as part of former defence minister Anatoly Serdyukov’s reforms. Nevertheless, the pace of Russian reconstitution in many areas makes the availability of a Russian ground force comparable to the one that invaded Ukraine on 24 February 2022 plausible enough to bear consideration.

Specific land capabilities, such as deep-strike missiles like the PrSM and the ATACMS, may have greater cross-theatre relevance, as they can be used to strike vessels in port or even to contribute to counter-airbase missions. However, while the possession of these missiles by Taiwan at the outset of a conflict may be relevant, it is unlikely that the US will be able to ship additional missiles to Taiwan under contested conditions, and most ground-based fires, with the exception of the US Army’s intermediate-range hypersonics, largely lack the reach to strike China from anywhere else in the first island chain.

The major bottlenecks in the deployment of the US Army to Europe would probably be in the areas of air defence and logistical support. Since the US Army is responsible for air defence as a function of the Key West Agreement, it would likely see its air-defence capabilities entirely consumed by a Pacific war. Any US Army deployment to Europe would thus depend on the availability of adequate European air defences (without which ground forces could not deploy).

US strategic sealift would necessarily be strained by a Pacific deployment, and some of this capability will be provided by the US Army. At the time of writing, there is limited European capacity to provide strategic sealift, as the movement of US forces across the Atlantic has largely been a US activity. NATO maintains a sealift consortium, to which 11 countries contribute 15 vessels, but this represents a limited capability. Airlift may represent another means of providing inter-theatre mobility to US forces, as during the Cold War, although this will likely only partially mitigate bottlenecks in mobility.

In effect, while many components of US land power may in principle remain available for use in Europe – if policy allows – even in the face of an Indo-Pacific contingency, this depends to a considerable degree on the ability of European states to fill gaps in key enablers that allow a ground force to both cross the Atlantic and remain safe against a range of air and missile threats while in theatre.

Conclusions: Manageable But Growing Cracks

The findings in this report suggest that while there will undoubtedly be resource constraints within Europe during a decade of acute risk in the Pacific, these constraints should be parsed, given that not all assets are fungible. This is not to suggest that major capability gaps do not exist within European militaries, nor that they must not be closed. But a more granular analysis of these gaps can help identify immediate priority areas.

In certain areas, the analysis for this report produced counterintuitive findings. In particular, despite airpower and air-defence assets being in high demand across the European and Indo-Pacific theatres, the munition and interceptor types required were not in all instances pulled in two directions by conflicting demand signals. In particular, SEAD munitions such as the AARGM-ER may have limited relevance to a Pacific campaign. This largely stems from the fact that strikes against the Chinese mainland at a scale that might alter the balance of power over Taiwan are not only increasingly unviable, but also superfluous, insofar as mutual air denial over Taiwan and the ability to target destroyers and cruisers, as well as the amphibious vessels they protect in and around the island, are potentially sufficient to enable the failure of a Chinese invasion. If, as some have argued, the US prioritises resourcing allied efforts as part of its deterrent, resourcing European SEAD efforts (which are currently constrained less by platforms than by munitions) is achievable by the US without undermining an Indo-Pacific campaign. As discussed in Chapter II, meaningful European gaps also exist in areas other than munitions – but material gaps may prove easiest to fill.

Air and missile defence is, similarly, a constrained capability, although some constraints are more acute than others. Available IAMD systems and capacity in terms of both hit-to-kill interceptors and blast fragmentation warheads are available to a limited degree in Europe. Unlike in the Pacific, however, the Russian ballistic threat is limited to a part of the theatre, and will be attenuated over time as a SEAD campaign takes effect. Moreover, capacity limitations can be mitigated through the more effective layering of defences against SRBMs. In the Pacific, by contrast, BMD is likely to be a persistent resource demand. Stocks of blast fragmentation interceptors needed for both air-to-air and cruise missile defence will be a resource heavily strained by a Pacific contingency.

In the maritime domain, surface lethality and ASW emerge as major European capability gaps, which is perhaps unsurprising given the maritime dimensions of the Pacific contingency to which US assets would be drawn.

While the US Army capabilities most relevant to the land domain do not necessarily have great relevance to an Indo-Pacific contingency, many of the enablers needed to move these assets to make US capabilities operational would probably need to be provided by European states.

In effect, then, the task of preparing for the Davidson Window in Europe should be seen as one of filling specific gaps in capacity as rapidly as possible, while others can be covered on a longer-term basis. To be sure, it is desirable for a number of reasons that European states mobilise the capacity to replicate the full spectrum of capabilities and enablers for which they currently rely on the US. Assuming that not all these capabilities can be delivered in a decade, however, there are specific areas to which resources should be targeted on an immediate basis. This report has sought to shed light on which areas might represent vulnerabilities. These areas should be targeted with urgency.

▲ Table 1: Summary of the Relative Risk of US Overstretch in Individual Areas. Source: The authors.

Sidharth Kaushal is the Senior Research Fellow, Sea Power in the Military Sciences research team at RUSI. His research covers the impact of technology on maritime doctrine in the 21st century and the role of sea power in a state’s grand strategy.

Juliana Suess is the former Research Fellow and Policy Lead on Space Security in the Military Sciences research team at RUSI. Her research interests include global space governance, counterspace capabilities and space warfare.