Executive summary

• Japan’s National security strategy (NSS) revisions were announced in December 2022. Since then, Japan has been implementing the plans in the NSS documents, including the procurement of counterstrike capability.
• This is important for the Australian Parliament as Australia and Japan have reaffirmed their commitment to the Special Strategic Partnership (2022), and Japan is mentioned 10 times in the National defence strategy (2024). As Australia strengthens its ‘minilateral’ security partnerships and defence industrial integration in the Indo-Pacific region – as indicated in the Integrated investment program (2024) – Australia’s integrated air and missile defence cooperation with the US and Japan is a high priority.
• The NSS plans have generated debate in the Japanese parliament and community, with particular concern for the defence budget, constitutional reinterpretation, and the counterstrike capability. Although the documents do not exhaustively clarify how the counterstrike capability would be used, when put in the context of potential contingencies involving Taiwan and the Korean peninsula, Japan’s counterstrike capability raises legal, diplomatic and practical questions regarding the nature of Japan’s security posture.
• This paper outlines 2 ways to clarify Japan’s strategic calculus for its counterstrike capability. One is to situate it in the regional security context, including the past 30- 40 years of missile development in Northeast Asia. The other is to trace its evolution within the closely integrated US-Japan security alliance and US Indo-Pacific strategy involving closer cooperation with allies and partners in the region. A third way, which involves a more independent security posture and expanded counterstrike options, is beyond the scope of this paper.
• Finally, due to rapid development in weapons technology, this paper concludes by noting how some current scholarship has addressed the implications of blurring boundaries between conventional and nuclear weapons. Specifically, it outlines how comprehensive institutional assessments of escalatory pathways and de-escalation mechanisms are needed as part of a wider renewal of security and arms control frameworks in the region for all countries involved.

Introduction

Amid a mounting arms race, including missile proliferation, in a fraught security and geopolitical environment in the Asia-Pacific region, the release by Japan’s Cabinet on 16 December 2022 of its 3 key security documents marked a major turning point in the nation’s exclusively defence-oriented policy (senshu bōei).

As the first National security strategy (NSS) since the Abe administration declared the right to collective self-defence in December 2013, the 2022 National security strategy, National defense strategy (NDS) and Defense buildup program (DBP) signify the most concrete shift away from the Yoshida Doctrine of ‘self-imposed (military) restraint’ during the postwar period.

The NSS policies realise long-pursued efforts by factions in the Liberal Democratic Party (LDP) to ‘normalise’ the nature and operating scope of Japan’s military. Under successive administrations (led by Nakasone Yasuhiro in 1987, Junichirō Koizumi in 2001–06, Abe Shinzō in 2017, and Suga Yoshihide in 2020), Japan has consistently increased military spending to build one of the world’s most powerful, top-tier forces. This includes ‘the most sophisticated ballistic missile defense system (BMD) outside of the United States’.

The NSS documents and the follow-up defence white paper, Defense of Japan 2023 (released 28 July 2023), underscore that the country faces ‘the most severe and complex security environment since World War II’ and emphasise the national will and capacity to ‘resist foreign invasion’. Although less complex than during the Cold War in Northeast Asia (1947–91), the main threats to Japan are listed as:

• significant qualitative and quantitative improvement in missile technologies in the region, including those of the Chinese PLA, DPRK (North Korea) and Russian forces
• China’s military activities around Taiwan and its territorial claims in the East and South China Seas
• a resurgence in Russian presence in the Asia-Pacific, and Russia’s ‘serious violation of international law’ in the prolonged war in Ukraine and its implications for Taiwan.

The NSS revisions have been welcomed by Japan’s international partners (including Australia) and met with opprobrium mainly from the countries listed as Japan’s primary threats – China, North Korea, and Russia. They have been described as marking a transition from an exclusively defensive to a type of offensive posture, or, what the US Ambassador to Japan Rahm Emanuel described as ‘alliance protection to alliance projection’. In transatlantic policy circles they were variously dubbed as a ‘zeitenwende’, ‘paradigm shift’, ‘game changer’, and as ‘the most positive security development in East Asia in this century’. After all, Japan’s decision to further ease constitutional limits on Japan’s military spending and weapons exports echoes successive US administrations dating back to the 1950s. Moreover, 90% of Japan’s defence acquisitions are from US arms manufacturers, which will increase by 15% as part of boosted market demand this decade for precision-guided munitions in the Asia-Pacific.

For Australia, much hinges on Japan’s ability to deliver its proposed revisions. To strengthen conventional deterrence, alongside intelligence-sharing and cyber resilience in its trilateral cooperation with Australia and the US and joint military exercises, in October 2024 Japan agreed to co-develop long-range missiles and joint munition production with Australia.

As some have noted, this could be mutually beneficial. The involvement of Japanese firms could accelerate Australian industrial base development objectives, while producing missiles in Australia could offer Japan a potential source of production and resupply and ease cost and production pressures in the event of major conflict in Northeast Asia. In addition, closer cooperation may further support the Royal Australian Navy’s SEA 3000 project to procure 11 general purpose frigates from 2026, if Japan’s Mitsubishi Heavy Industries was to be selected.

At the domestic level in Japan, however, the NSS announcement sparked popular and parliamentary opposition. Of particular concern are the decisions to override the post-1976 political convention of the 1% gross domestic product cap on military spending (to exceed 2% of GDP from 2027), to fund the hike in defence spending through public taxes, to acquire counterstrike capability, and to lift the de-facto ban on arms exports.

All up, Japan plans a total of 43 trillion yen (US$325 billion) for defence, which is a 56.5% increase, or 1.5 times the 27.47 trillion yen amount in the 2019–23 plan. In fiscal 2024, Japan’s defence budget rose for the eighth straight year to US$55.9 billion, while in fiscal 2025 it will rise again to US$59 billion. Based on current budgets, by 2027 Japan will be on track to increase its military spending from tenth (2022) to seventh in the world.

Given Japan’s 250% debt-to-GDP ratio, its already significant contribution to building and maintaining US military bases on its territory, competing budget demands and low public approval due to political scandal, however, the Kishida administration was forced to retreat from its proposed reliance on tax increases to pay for its budget. Despite offering some alternatives, the pressure was such that Prime Minister Kishida decided to not run for re-election.

As demonstrated by the current LDP minority government led by Prime Minister Ishiba, Australia will need to consider Japan’s recent political instability and its ability to achieve its national security goals. It may be less feasible, for example, for constitutional amendments to allow for collective self-defence to be passed.

In terms of actual procurements, Japan seeks to boost its ‘multi-domain defence force’ (pp. 53–55) through integrated capabilities and its defence industrial and technology base. This includes provisions for standoff, integrated air and missile defence, unmanned/autonomous, and long-range strike weapons; cross-domain operations, mobile deployment, and command-and-control and intelligence-related functions; and civil protection, sustainability and resilience.   

At the operational level, Japan has been emboldened as a close and ancillary player with the US in strategic power competition with China, to revise and strengthen its hard power capabilities in the region. In preparation for ‘protracted warfare’ (in contrast to a ‘short and sharp’ war) in the Indo-Pacific region, this involves a joint US-Japan pivot to the Nansei Shotō (Southwest Islands, or, Ryūkyū archipelago) and boosted US-JSDF joint military exercises.

In a increasingly complex security situation in East Asia, the procurement of advanced offensive capabilities such as Japan’s counterstrike missiles risks accelerating an arms race and lowering the threshold for large-scale conflict in the region. This paper explores Japan's legal requirements, and the ways in which it may use its conventional missile systems in the event of a major conflict over Taiwan or on the Korean peninsula, which includes the potential to hit specific targets on China’s mainland, including its nuclear forces and associated systems.

The potential military and very high human and infrastructure costs in a conflict over Taiwan (estimated at 10% of global GDP), should be a major incentive to all stakeholders to prioritise strategic balancing while advancing regional security through diplomatic negotiation, confidence-building measures and escalation management towards détente, supported by an updated arms control regime.

Japan’s counterstrike – implications

Constitutionality

Article 9 of Japan’s constitution prohibits the use of force and the maintenance of armed forces or ‘other war potential’ and denies the rights of belligerency.

Since their establishment in 1954, the now 250,000-strong all-volunteer Japan Self-Defense Forces (JSDF) have been primarily engaged in public service and disaster relief. The carefully named JSDF has always had the remit to use the minimum force necessary to defend the territory and population of Japan, alongside US forces deployed on Japanese soil. Its mission has also been extended to deployment on logistics and troop support missions, including UN Peacekeeping Operations, such as in Iraq in 2003.

As part of its ‘pro-active contribution to peace’ policy, the Abe Government (2012–20) set up the foundations to expand its military activities. In 2014, the new National Security Council, established under the first National security strategy (2013), declared the right of the JSDF to collective self-defence. According to the Cabinet Secretariat, this stipulates the use of force ‘to the minimum extent necessary’ as not exclusively for self-defence, but also ‘when an armed attack against a foreign country that is in a close relationship with Japan occurs and … when there is no other appropriate means available to repel the attack’ (pp. 7–8).

With expanded military obligations under the 2015 US-Japan Defense Guidelines, and the precedent of constitutional revision set by Abe’s grandfather and former prime minister Kishi Nobusuke, Abe’s administration passed the 2015 Peace and Security Preservation Legislation (‘Collective Self-Defence legislation’) amid significant popular and parliamentary protest. This confirmed that the JSDF would participate in ‘limited’ collective self-defence, such as aiding US forces in combat. It also further loosened constitutional limits on Japan’s defence industry and arms exports.

Following the ‘Abe doctrine’, Japan’s 2022 National defense strategy underscores that counterstrike capabilities are ‘key to deterring invasion against Japan’, with a particular focus on deterring China (especially in the East China Sea and along Japan’s Southwestern Islands). Using counterstrike capabilities, the NDS states Japan’s intention is to:

… possess a capability that makes the opponent realize that the goal of invasion is not achievable by military means, and that the damage the opponent will incur makes the invasion not worth the cost. (p. 11)

There is little context in the NSS documents and official statements to explain why China would invade Japan’s territories.

Public and parliamentary debate in Japan has engaged the legal and policy circumstances under which a counterstrike, prior to missile launch, would take Japan over the threshold from a defensive to an offensive posture.

Japanese officials claim that Japan would utilise counterstrikes under 3 conditions:

• when Japan’s national survival is under threat by armed attack against Japan or a foreign country with which it has a close relationship
• if there are no other appropriate measures to remove the threat
• if the use of force is limited to a minimum necessity.

Critics maintain, however, that a counterstrike may violate constitutional and international law frameworks for the use of force on foreign territory, and that it may equate to full participation in ‘collective defence’.  

The NSS documents themselves explicitly rule out pre-emptive strikes and state that the new capability is to:

… enable Japan to mount effective counterstrikes against the opponent to prevent further attacks while defending against incoming missiles by means of the missile defense network … as long as it is deemed that there are no other means to defend against attack … (p. 19)

The documents restrict long-range conventional missile strikes to targeting ‘enemy base attack capability’ (since renamed ‘enemy counterattack capability’, ‘counterstrike capability’, or ‘standoff defence capability’), and only in the case of prior armed attacks against Japan by an adversary. As outlined by Masahiro Kurosaki, Professor of International Law, it has been Japan’s longstanding position on the issue that:

… the mere likelihood or threat of armed attack does not authorize the exercise of the right to self-defense whatsoever. In other words, neither preemptive strike nor preventive war is permissible. 

Despite a lack of clarity in the NSS documents on scenarios in which Japan’s counterstrike might be used, exploring how Japan, within its upgraded Japan-US security alliance, may be involved in a conflict in the Taiwan Strait or the Korean Peninsula might provide further insight.

Taiwan contingency

In the event of a cross-strait conflict, the NSS reaffirms Japan’s official position as: 

Peace and stability across the Taiwan Strait [are] an indispensable element for the security and prosperity of the international community, and Japan will continue to make various efforts based on its position that the cross-strait issues are expected to be resolved peacefully. (p. 14)

In such a conflict, Japan’s missile defence systems would likely be used to intercept mid-air any missiles targeting JSDF forces (and may also be used to protect US forces under attack). As stated in the NDS (p. 23), JSDF counterstrike capabilities, on the other hand, would be used against ‘vessels and landing forces invading Japan, including its remote islands, from locations outside of threat zones’. 

In recent years, former president Biden eroded the US policy of ‘strategic ambiguity’ towards Taiwan, with a visit by House Speaker Nancy Pelosi to Taiwan, by boosting US arms sales to Taiwan, by increasing military drills around Taiwan and deploying US special forces on Taiwan. 

The late prime minister Abe’s 2006 position was that a ‘Taiwan contingency is a Japan contingency’ (which he reiterated in 2021). More recently, Japanese leaders such as former ministers Fumio Kishida, Nobuo Kishi, and Tarō Kōno, have also indicated their support for counterstrikes to exceed localised strikes in defence of its small islands, and to include enemy base strikes as ‘within the scope of self-defense’.

These remarks provoked parliamentary calls for constitutional debate, and clarifications from the former director-general of the Cabinet Legislation Bureau, Masahiro Sakata, who reportedly reiterated:

While it is in the nature of the government to try to break free from the restraints of the Constitution, which binds its activities, (acquiring the enemy base strike capability) goes beyond the exclusively defensive posture.

Some strategists external to government, such as Shinichi Kitaoka and Satoru Mori, have argued (fn. 55) that in addition to ‘downstream’ targets, such as individual warships, Japan should include ‘upstream’ counterstrike targets on China’s mainland: ‘air force bases, naval bases, supply and logistical points, anti-aircraft radar sites, communications centers, command centers, and other fixed targets’.

To circumvent the likelihood of constitutional wrangling over Japan’s requirements to allow the ‘use of force’ in ‘self-defence’ (Article 9), strategic planners in Japan have sought to distinguish between ‘preventative’ (to prevent a future attack) and ‘anticipatory’ or ‘pre-emptive’ (to prevent an imminent attack) strikes.

Most states seek to justify the use of force as self-defence, and in international law it is widely accepted that ‘pre-emptive self-defence’ is defined as the anticipatory use of force in the case of an imminent or more remote threat of attack.

Japanese law also requires the demonstration of ‘necessity’ for self-defence, which is based on an assessment of the intent and surrounding facts concerning the alleged inevitability and ‘imminence’ of an adversary’s use of force against Japan. For example, according to the Caroline standard, 'imminence’ requires that there be no time to pursue non-forcible measures with a reasonable chance of averting or stopping the attack. Therefore, only if the requirement of ‘necessity’ is met, would it be lawful for Japan to initiate pre-emptive and proportional self-defence to eliminate the attack.

Although opinion remains divided on Japan’s level of involvement in a Taiwan contingency, it is generally understood that at the request of the US, Japan would likely declare a state of emergency and invoke its Article V collective self-defence obligations to ‘commit its armed forces … to assist Taiwan together with the United States’, even if it is not attacked first.

Given that the US doctrine of pre-emption as defined in the 2002 National security strategy (Section V) allows for the use of force without evidence of an imminent attack when there is a perceived existential threat to the United States or its allies, Japan may find itself more readily embroiled in a cross-strait conflict.

The Korean Peninsula

Since the conservative President Yoon Suk-yeol assumed power in late 2022, public approval for the government in South Korea has steadily declined and the population is polarised on a range of issues, including Japan’s security policy. This was demonstrated in the defeat of Yoon’s People Power Party in the National Assembly election in April 2024, and the impeachment on 14 December of President Yoon and Prime Minister Han Duck-soo due to Yoon’s failed bid to impose martial law on 3 December. Since then, Yoon has been released from jail for his criminal trial over his martial law decree with the legal period of his formal arrest having expired before he was indicted. The Constitutional Court has until June to issue a ruling on Yoon’s impeachment case.

In 2022, President Yoon expressed support for Japan’s counterstrike decision in the context of increased North Korean missile testing, including around 37 North Korean short- and medium-range missile launches in that year alone. However, centre and left camps and several public commentators have adhered to the orthodox policy line that ‘Japan should transparently strengthen its defense capabilities in a way that contributes to regional stability while complying with its pacifist constitution’.

More specifically, Seoul’s security planners are concerned that a less-experienced partner such as Japan may overreact to a security situation on the Peninsula and deploy its independent counterstrike capability, creating an unwanted escalation spiral. This may lead to an ‘allied entrapment’ scenario (drawing in nuclear-armed powers such as the US and China).

For example, perceiving an existential threat from a North Korean one-off conventional strike on a US base in South Korea, Japan may opt to conduct a unilateral pre-emptive strike without prior consultation using hypersonic weapons against North Korean launchers and sites. North Korea may interpret this to be a counterforce attack, coordinated between Japan, South Korea and the US and escalate to a ‘massive attack’ against the South, triggering wider escalation. Japan and South Korea have revived a high-level intelligence-sharing agreement (General Security of Military Information Agreement – GSOMIA), which North Korea is aware of.

As such, South Korean security analysts have called for Japan’s further assurance that its counterstrike option:

• is embedded within a joint US-Japan security framework
• includes extensive intelligence-sharing (within the trilateral framework)
• involves logistical support to US forces in the case of a Korean contingency.

The JSDF, for the time being, remains reliant upon US intelligence, surveillance, reconnaissance and targeting assets for access-denied areas, and for information collection and processing, and joint targeting coordination. However, Japan’s new capability increases incentives to pre-emption and places further pressure on the capacity of intelligence and security calculations (and decision-making windows) in all countries involved. This potentially increases the risk of miscalculation.

Missile proliferation in the region

It is also important to situate Japan’s counterstrike procurement in the context of missile proliferation in Northeast Asia. Contrary to perceptions of a ‘defenceless’ or ‘vulnerable’ pacifist Japan faced with an unprecedented military buildup by an aggressive state in the region, Japan’s missile development within its overall military modernisation, conducted jointly with the US, has been underway for much longer and at a greater scale than is typically understood.

Japan began its own missile development under its space program in 1955. As the US’s ‘strategic hub’ in the western Pacific under the Japan-US mutual security treaty (renewed from the San Francisco Treaty 1951), Japan has also been a long-term host to US weapons systems (including missile and nuclear weapons systems) on US bases and US platforms through its ports and airfields. During the Cold War, these included US tactical and strategic nuclear weapons stored on US-controlled Okinawa (1954–72), as well as US tactical nuclear missiles on South Korea (1958–91) and on Taiwan, the Philippines, Guam and some Pacific Islands (1958–77).

In 1985, Japan signed an agreement with the US to produce the Patriot missile-radar (PAC-2) system. In 2003, it further agreed to jointly develop Aegis system-equipped vessels (ASEV) (Kongo-class guided missile destroyers), including AN/TPY-2 (X-band) radar and Tier-1 (lower tier) SM-3 interceptors. The Aegis destroyers were deployed in 2007 and their number is to be increased from 8 to 10 with 2 new ASEVs with integrated air and missile defence capabilities (including  radar and tracking upgrades) by 2027–28.

Under the second Abe administration in 2012, Japan deployed the SM-3 Block IIA interceptor system, becoming the only country outside the US to possess both low- and upper-tier defences. It also loosened its export restrictions and exported this system to Romania (Deveslu) and Poland (Redzikowo).

By 2018, Japan had acquired longer-range standoff weapons, including for F-35s and F-15s (900–1,900 km range). And since 2022, Japan accelerated missile procurement for what is described as ‘inter-island long-range fire systems for remote island defense’. This includes Tomahawk cruise missiles, upgraded Type 12 missiles, air-to-surface cruise and standoff missiles, and hypersonic cruise and hypersonic glide missiles and interceptors (and in future, laser weapons).

While not dismissing Japan’s legal constraint of self-defence, Japan is developing ‘the technical capability for deep precision strikes against targets’ on China’s mainland and on the Korean peninsula in close coordination with US strategic and operational doctrine. As noted by security analyst Masashi Murano, the likelihood of Japan participating in standoff and long-range strikes during a conflict has undoubtedly increased (in particular, against China’s A2/AD strategy of denial, as outlined below).

One potential risk posed by Japan’s increased missile capability and deployments around the Southwest Island chain, as noted by researchers, is the ambiguity of the Air Defence Identification Zones (ADIZs) in terms of legality, function and performance (see Figure 1). Originally a US initiative to contain Moscow’s (and eventually Beijing’s) new nuclear capabilities in the 1950s and 1960s, the ADIZs’ operations in overlapping zones have no consensus or formal agreement on respective claims.

Figure 1           Air Defence Identification Zones in East Asia and Japan’s Type-12 and hypersonic missile ranges

Source: Derived from Maximilian Dörrbecker (Chumwa) (Wikimedia Commons)

On the Korean peninsula, North Korea, a state that has undergone prolonged ‘fortressisation’ in the backdrop of the frozen status of the Korean War, has set about attaining a credible, asymmetric deterrent due to inferior conventional forces. Without a formal security guarantee in the post-1991 environment, in an action-reaction dynamic, the DPRK’s proliferation of short to long-range missile capabilities (including nuclear) has been to improve its chances of survival. Its missile testing and exports can be understood as part of a pattern with regular US-South Korea-Japan large-scale joint military exercises along North Korean borders (since the 1980s), the US roll-out of ground missile defence, and a prolonged sanctions regime against the DPRK.

South Korea, in coordination with the US, has also built up an extensive inventory of missiles, including hypersonic and integrated missile defence technology, to enable ‘counter-asymmetric’ operational plans against North Korea. South Korea’s 3K system, informed by its ‘Strategic Target Strike’ doctrine and under the US-South Korea combined forces command arrangement (over 550,000 ROK troops and 28,500 US troops), would see pre-emptive ‘decapitation strikes’ and/or ‘conventional counterforce’ strikes in the event of an actual or perceived North Korean attack.

South Korea’s missile capabilities also include the US-supplied Terminal High-Altitude Area Defence (THAAD – with AN/TPY-2 radar and space-based tracking), installed in 2017 and which doubles as an early warning of North Korean or Chinese launches for US missile systems in Alaska and California. In 2021, South Korea obtained US approval for missiles with lengthened range, increased payloads, and solid fuel propellants. That year, South Korea was the first non-nuclear weapons state to acquire Submarine Launched Ballistic Missile capability and is developing ship-launched ballistic missiles. Going against the moratorium agreed between the US and DPRK, the Ulchi Freedom Shield exercises were resumed in 2022, bolstered by the US deployment of a B-52 and a nuclear submarine to South Korea.

In this action-reaction cycle of regional proliferation, North Korea most recently demonstrated its variants of solid-propellant missiles, including hypersonic missiles, and launched what it has called a ‘nuclear powered strategic guided missile submarine’.

Meanwhile, China’s military modernisation program (including its Civil-Military Fusion initiative), enabled by its continuous economic growth, has been a concerted effort since the 1990s to catch up with top-tier militaries and achieve a ‘world class military by 2049’. 

In the 1990s, China had a much smaller military budget and inferior military assets compared to those of the US and Japan and possessed a limited number of short-range (DF-15) and medium-range (DF-21) ballistic missiles which could reach Taiwan and South Korea. Since US President Clinton ordered 2 aircraft carrier groups to the Taiwan Straits in 1995 during a crisis concerning the status of Taiwan, China began to develop an Anti-Access/Area Denial (A2/AD) (‘counter-intervention’) strategy to reduce US freedom of manoeuvre in China’s littoral perimeter. In terms of missile proliferation, China’s A2/AD now involves the deployment of precision-guided missiles (currently numbering 1,500–1,900), including anti-ship dual-use DF-21D (1,550 km range), DF-26 (3,000–5,500 km), and DF-17 (and other hypersonic) missiles. These capabilities are intended to hold at a distance US and allied naval and air forces and reduce their capacity to project power into China’s territory should conflict break out.

The US AirSea Battle concept (ASB, later known as the ‘Joint Concept for Access and Maneuver in the Global Commons’ – JAM-GC)), which is to counter China’s A2/AD in the Western Pacific, was designed in 2009 and announced in 2010. This marked the US shift in strategic priorities to East Asia, as indicated in the US Pivot to Asia policy announced in Canberra in December 2011 and the 2012 Joint Operational Access Concept (JOAC). ASB, as it has continued to be developed, involves US forces ‘blinding’ PLA satellite networks to gain battlefield access and disrupt the PLA’s C4ISR (command, control, communications, computers, intelligence, surveillance, and reconnaissance) and missile systems.

Since 2011, amid accelerating regional proliferation, China has continued its modernisation plans, including the procurement of advanced fighter aircraft (such as the J-20, J-36, and J-XX); increasing its navy battle force, including 3 aircraft carriers to date, and new amphibious landing equipment; improving cybersecurity technology; and strengthening its anti-aircraft/satellite/missile systems with over the horizon and new anti-stealth capable radar, which also includes anti-satellite (ASAT) weapons testing (along with the US, Russia, and India).

Although Japan’s new strategy documents highlight China’s military expansionism and North Korea’s missile threats as presenting ‘the severest and most complicated national security environment since the end of the war', researchers have also cautioned that China ‘currently represents little or no direct threat to the US due to its limited capabilities to project power outside of its immediate region’. Moreover, they warn that ‘more military spending to counter China will not lead to greater security’, and that a war between China and the US over the status of Taiwan would ‘come at a high cost for all concerned and might even escalate into a nuclear confrontation’.

US-Japan strategic transition

In the transformation of the security environment and missile technologies (such as land-based missile capabilities) in the region since around 2011, Japan and South Korea (and Australia, the Philippines and Singapore) have strengthened security partnerships with the US, including the latter’s presence on their territories, and in reciprocal relation to regional security threats.  

Part of the US shift to prioritise the Asia-Pacific in its strategic interests was the idea, as reported by RAND researchers in 2013, to deploy land-based anti-ship missiles (ASM) among a coalition of partner countries in the region.

Since 2013, Japan has fortified and conducted joint amphibious and electronic warfare exercises on and around its archipelagic Southwest. Other partner countries (including Australia) also partake in joint naval exercises, including amphibious operations, in the area (and in northern Japan, The Philippines, Guam, and South China Sea). While supporters welcome the socio-economic gains from the activity in the area, local critics, including the Okinawa Governor Denny Tamaki, point to insufficient consultation and inadequate civil defence in frontline communities. They also warn of the ‘escalatory’ nature of militarisation of the area.

In 2016, analysis by RAND of a future Sino-US war warned of a temporal window before China gains military parity with the US in the Western Pacific. This was later taken up by high-ranking US military officials (that is, by 2025 in the ‘Minihan window’ and by 2027 in the ‘Davidson window’), to the effect that President Xi had ordered an ‘invasion deadline’ for 2027. Then-chairman of the Joint Chiefs of Staff Mark Milley reportedly said that Davidson’s comments were based on a speech from Xi, calling on China’s military to ‘develop capabilities to seize Taiwan and move it from 2035 to 2027’. This was further qualified in 2023 by CIA director Bill Burns who confirmed that Xi’s unconfirmed order was  ‘a matter of intelligence’, but that ‘being ready’ did not mean a ‘decision to invade’. By then, however, the story had been widely reported around the world. The ‘survivability of Taiwan’ was then used as further justification for Japan and other US allies and partners to prepare for war with China.

Since the normalisation of US-China relations in 1979, in maintaining strategic ambiguity between the two nations, Beijing has stated that it aims for peaceful unification with Taiwan, but it has never ruled out military action as a means of resolving Taiwan’s status. It has also consistently maintained that the settlement of the Taiwan question is an internal matter, in which external actors should not interfere.

Meanwhile Washington has maintained arms sales to Taiwan, to indicate its ongoing support for Taiwan’s de facto sovereignty as part of the 1979 Taiwan Relations Act. It also leaves open the possibility of cessation of such sales if China peacefully resolves the Taiwan issue.

In 2017, the Trump administration announced its ‘free and open Indo-Pacific’ framework (adapting the concept introduced by Abe Shinzō in 2006). The US 2018 National defense strategy (2019–23) then adopted a ‘peace through strength’ approach, which named China and Russia as ‘long-term peer strategic competitors’. This strategy planned for a great power war in the Indo-Pacific by boosting capability and lethality, strengthening established and new security partnerships, and enabling integrated joint force all-domain operations. At the time, the framework was criticised by some for ‘provoking Beijing, alarming other Asian nations, and driving the region toward a highly tense, zero-sum competition’.

In Japan’s National Defense Program Guidelines for fiscal 2019 (December 2018), North Korea was replaced by China as Japan’s top security threat. The guidelines also announced Japan’s procurement of a ‘standoff’ capability – the capability to strike invading forces from outside their range of attack.

In 2019, China released ‘China and the world in the new era’ outlining its competitive strategy with the US. In 2021, President Xi announced China’s ongoing plans for peaceful national reunification and national rejuvenation.

In this period, the first Trump administration opened the floodgates by declaring the US withdrawal from the bilateral Intermediate-Range Nuclear Forces Treaty (INF 1987), alleging Russian non-compliance with the treaty. It then immediately tested a land-based cruise missile from a Mark 41 Vertical Launch System, used in the Aegis missile defence system. In response, Russia cited US non-compliance and followed suit (although Russia maintained a self-imposed moratorium on INF-range missiles until late 2024). The demise of the INF Treaty followed that of the Anti-Ballistic Missile (ABM) Treaty, which the US withdrew from in December 2001 (official withdrawal in June 2002) and the US refusal to ratify the Strategic Arms Reduction Treaty (START II). In response to the US ABM withdrawal, Russia also withdrew from the ABM Treaty and START II.

With the path cleared of INF restrictions, the US prepared to deploy ground-launched intermediate-range missiles as part of its archipelagic strategy to build a ‘missile wall’ along the first island chain. The 2019 Missile defense review described a ‘shift of burden’ plan as the US:

… seek[s] to integrate US, allied, and partner capabilities for active missile defense and, as appropriate, attack operations capable of striking the entire range of infrastructure supporting adversary offensive missile operations. (p. 47)

In 2020, Japan’s Ministry of Defense abruptly cancelled its land-based Aegis Ashore missile interceptor system, and then-Defence Minister Tarō Kōno declared his preference for a pre-emptive first-strike capability, which was later approved by Prime Minister Abe and the NSC. Kōno argued:

It would not be unconstitutional to strike an enemy launch pad or base before a missile launch, instead of waiting for the missile's booster phase. [emphasis added]

Once again, some analysts expressed concern about the US missile-sharing plan, and some countries adopted a studied ambivalence to hedge against the impacts of regional great power rivalry. As further incentive, however, the US then offered to ‘empower’ its partners by transferring operational control of the systems.

In 2021, as part of the US’s Pacific Deterrence Initiative, the US Indo-Pacific Command announced its plan (US$27 billion by 2027) to field an:

Integrated Joint Force with precision-strike networks … along the First Island Chain, integrated air and missile defense in the Second Island Chain, and a distributed force posture that provides the ability to preserve stability, and if needed, disperse and sustain combat operations for extended periods.

For example, the 2018 US-Philippine cooperation to build missile systems has since been expanded to include the deployment of medium-range Typhon missile systems (over 1,600 km range) to US bases in the northern Philippines.

As part of its steady roll out of capabilities in the region, the US 2022 National defense strategy outlined closer cooperation in layered integrated air and missile defence for Japan, the ROK, and Australia (and Taiwan). As later confirmed in 2024, the integrated air and missile defence network involves shared real-time data from US reconnaissance drone fleets and satellites and sensors (C4ISR enablers) for identifying and tracking targets.

These longer-range missile capabilities for dispersed operations forming a ring of land-based anti-ship missiles would be integrated with US joint force efforts to continue to develop new missile systems, to harness the full-spectrum of information and coordinated with expeditionary operations across US Army, Marine, and Air Forces to weaken China’s A2/AD defensive bubble in the region.

It follows that Japan’s ‘counterstrike capability’, as stated in the DBP (p. 9), ‘will be conducted under unified command and control based on joint operations’ for dispersed, networked archipelagic warfare (among other operations) along the first and second island chains in the South China Sea and the Western Pacific. Moreover, as Japan expands government and military satellite constellations (and incorporates commercial satellite data), it will remain reliant on US satellites (for target identification and assessment) for the foreseeable future. For this purpose, US military command will be more closely integrated in US-Japan command and control (C2) frameworks.

Proliferation and escalation risk

With the caveat that Japan is limited by its exclusive defence posture, the above outline situates Japan’s counterstrike capability in the context of wider regional missile proliferation and US-deployment of conventional long-range preemptive strike capabilities. While the US measures are intended to strengthen the deterrent quotient by further complicating Beijing’s strategic calculations, it is worth further noting that the blurring of conventional and nuclear missile types and systems at the same time also risks further proliferation and escalation spirals in the security environment.

In the context of increased uncertainty and escalation risk exacerbated by doctrines to expand missile proliferation, allow for preemptive strike, and lower the threshold for nuclear use, there is the risk of an arms race dynamic intensifying in the region.   

Conclusion

Japan’s 2022 National security strategy is a historic marker of how the country is positioning itself in the wider security context of US-China geopolitical competition, including in potential escalation(s) over Taiwan and in the western Pacific, the Korean Peninsula, the South China Sea, and elsewhere. It underscores a significant shift in Japan’s strategic calculus.

In the security dilemma in East Asia, the NSS documents and supporting statements and initiatives (including with regional partners such as Australia) indicate Japan’s boosting of hard-power capabilities as part of its strategic outlook.

Although the US-Japan alliance is robust, Japan’s (and South Korea’s) dwindling restraint and increased investments in long-range strike capabilities are also part of a re-orientation towards self-reliance and a hedge against declining US influence in the region (Panda 2023, pp. 39; 70). This response indicates how countries are coping with uncertainty by preparing for several possible outcomes in the region.

For example, in one scenario, as argued by critics of US strategy in the Indo-Pacific:

Efforts by the United States to restore military dominance in the region through offensive strategies of control are unlikely to succeed. Not only would such efforts prove financially unsustainable; they could also backfire by exacerbating the risk of crises, conflict, and rapid escalation in a war.

In another scenario, however, Japan may continue to influence its US partner as it seeks to maintain control in the region to control an escalation spiral between the US and China. This would further Japan’s greater security and may cement its role as a diplomatic leader in the region over the longer term.

In any case, preparedness outside of actual kinetic conflict in the region involving detailed, scenario-based policy and military consultation in escalation dynamics (including unintentional pathways) at the institutional level among allies and adversaries may help minimise or avoid escalation risks if a crisis presents itself (Panda 2023, pp. 63–76).

Confidence-building measures would include reinvigorated diplomatic initiatives among countries in the region, detailed context and understanding of all parties’ threat perceptions, permanent communication hotlines and accurate missile-tracking and identification technologies. Dialogue mechanisms to defuse tensions and negotiate new security frameworks have also been recommended (including agreed limitations or reductions in offensive missile and other weapons, arms control and non-proliferation agreements, and delimitation of peace zones).

At the same time, the increasing insecurity from the blurred boundary between conventional and nuclear weapons (including low-yield nuclear weapons) and continuing pressure by non-nuclear weapons states like Japan for the US to boost its theatre-focused capabilities, only creates a further need for mutual agreement between nuclear weapons states to adopt no-first-use postures and to establish off-ramps from the accelerating proliferation and escalation spiral in East Asia.