The contemporary transformation of the Japanese army

Published on :

7 May 2026

This fact sheet looks at the contemporary transformation of the Japanese army. It highlights the major increase in the country's military budgets in recent years, as well as the new desire to acquire offensive capabilities. It then analyses the reasons for and some of the limitations of these singular developments, before concluding with a look at the outlook for Japan, particularly with regard to its essential alliance with the United States.

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Summary

Japan has transformed its defence capabilities in recent years: relaxing certain constitutional constraints inherited from the Second World War, the country has increased its military spending and is now investing in offensive capabilities;

The transformation underway can only be understood in the context of increasing regional tensions - around Taiwan - and international tensions - in Ukraine; Japan's rise to military power remains constrained by a number of challenges, and the country remains highly dependent on its partnerships, particularly with the United States;

For the future, it is in Japan's interest to clarify the military responsibilities it wishes to assume individually and those shared in the event of a major conflict in East Asia, as well as to diversify its strategic partnerships.

Context - From self-defence to collective defence?

Heavily dependent on international trade - particularly maritime trade - for its economic development, Japan today sees itself as the promoter of an open Indo-Pacific region, governed by the principles of the rule of law, freedom of navigation and free trade, the defence of strong connectivity, and a deliberate commitment to peace and security.

Japan is often described as a «pacifist» country. This designation stems from its 1947 constitution, drafted after the surrender of September 1945 and in the context of the occupation of the country by the United States. Article 9 states that Tokyo «forever renounces war as a sovereign right of the nation and the threat or use of force as a means of settling international disputes».»^[1]. In the immediate post-war period, the consequence was a complete renunciation of the possession of forces.

Nevertheless, the situation changed rapidly. Eager to have an ally in the region, the United States agreed to the creation of the Japanese Self-Defence Forces (SDF) in 1954 following the Korean War. An interpretation of Article 9 then allowed Tokyo to build up sufficient forces to defend itself in the event of an attack, without being able to take offensive action. Three conditions authorising the possible use of force were set out in 1954: there must be a threat to national survival; no other means can avert the danger; and the use of force must be limited to the strict minimum. In return for this limitation, the United States promised to defend Japan by signing an alliance in 1960: the Treaty on Mutual Cooperation and Security.

This concept of the use of force based exclusively on self-defence dominated the decades that followed, including after the end of the Cold War. However, Japan's military stance hardened in recent years. Several constitutional restrictions were relaxed. Significant developments took place in 2014-2015. Reforms reinterpreted Article 9 of the Constitution to allow the right to self-defence, subject to certain conditions. collective. Even if the national territory is not targeted, the SDF can support partners under attack if Japan considers that its survival is incidentally threatened in this way. Japanese forces can also take part in combat missions abroad.

Three key documents published in December 2022 confirm the real increase in the power of the SDF, moving towards a more direct alignment of the country's economic and military powers: the National Security Strategy, the National Defence Strategy and the Defence Strengthening Programme. Tokyo is announcing a doubling of its defence spending. While the country had previously respected an unofficial ceiling of 1 % of GDP, it is committed to increasing its spending to 2 % by 2027. The graphs below show the evolution of Japanese military spending in recent years, both in absolute terms and as a percentage of national GDP.

The shift in 2022 is clearly observable. In 2024, Japan will have the tenth largest military budget in the world, according to the Stockholm International Peace Research Institute (SIPRI). In concrete terms, the increase in power is reflected in a number of ways. The first is an effort to rearm and develop new capabilities. Perhaps the most symbolic, and consequently the most controversial, of the changes in this area is the decision to acquire, in addition to anti-missile defences, retaliatory capabilities via long-range precision missiles capable of striking targets on the Asian continent. Tokyo is relying on the purchase of Tomahawk and local solutions. This ability to reach China and North Korea - a first since the Second World War - moves away from a purely defensive logic. Another area illustrating Japan's growing power is combat aviation. Tokyo plans to have 430 fighter aircraft by 2032, notably through the acquisition of 147 American F-35s: the largest fleet of F-35s outside the United States. Other sectors are also specifically targeted, such as building up ammunition stocks, correcting recognised shortcomings in cyber defence, strengthening the defence technological and industrial base (DTIB) and arms exports. Finally, Tokyo aims to strengthen the interoperability of its forces and its strategic partnerships with the United States and other countries sharing its objectives in the region. The election of Prime Minister Sanae Takaichi in October 2025 is unlikely to alter this move towards a more assertive military stance. As soon as she took office, the leader stated her intention to accelerate Japan's military build-up, declaring that the country would reach its target of 2 % of GDP before the scheduled date. A revision of the national security strategy was quickly announced. Moving from a defensive posture to one of «proactive pacifism» according to some^[2], Tokyo is thus demonstrating its determination to make a more active contribution to maintaining peace and security in the Indo-Pacific.

Analysis - A response to the international context, but severe constraints

The ongoing transformation of the Japanese army certainly reflects a sense of vulnerability in the context of rising tensions both regionally and globally. Japan's strategic documents for 2022 state that «[the] security environment is more serious and complex than at any time since the end of the Second World War».»^[3]. The texts expressly identify China's growing military capabilities - Beijing, which disputes certain islands with Japan, is designated as the greatest «strategic challenge».»^[4] - and North Korea's nuclear and ballistic capabilities as direct threats to the country's security. More broadly, the documents point to Russia's invasion of Ukraine as a possible prelude to future regional conflict. «Today's Ukraine could be tomorrow's East Asia».»^[5] A high-intensity war zone.

The strengthening of our defence capabilities is therefore aimed at dissuading China, Russia and North Korea from any destabilising actions at regional level. The fact that these nuclear powers are themselves strengthening their strategic partnerships probably only increases Japan's sense of vulnerability. One notable point today is the existence of a certain consensus in Japan on the need for a more robust defence capability. The main political parties and the population are overwhelmingly in favour of increasing defence spending. The threat - from China in particular - is therefore not only perceived at the level of the country's leadership, but is widespread within a society that has been recognised as anti-militaristic since the post-Second World War period.

Takaichi's arrival in power exacerbated Sino-Japanese tensions at the end of 2025. The Prime Minister told the Japanese parliament that an attack by Beijing on Taiwan could be perceived as an existential threat to Japan, justifying armed intervention. Japan would in fact be in the front line of a conflict over Taiwan - Japan's most westerly island lies 110km from Taiwan - and Beijing's seizure of Taipei would leave Tokyo very isolated. China reacted violently to these statements by suspending certain imports and exports to Japan, advising its citizens against travelling there and stepping up its military exercises in the sub-region - a strategic signal.

Even so, Japan faces a number of challenges in its bid to regain military power. The first is financial. So far, the Japanese government has honoured its promises to increase military spending, but this has been achieved partly through an accounting trick. Expenditure such as that on the coastguard is now included in defence spending, which was not the case before. Some experts believe that it will be difficult to go any further given the constraints on the country's budget, which is already heavily in debt. The government is reluctant to raise the debt ceiling for current expenditure, while raising taxes or cutting other public spending would be politically costly. The depreciation of the Japanese yen is also weighing on foreign military purchases: the initial procurement strategy was based on an exchange rate of 108 yen to the US dollar, but this is now much more unfavourable for Japan.

The second challenge is demography. Japan has one of the lowest birth rates in the world and, as illustrated in the graph below, its population is falling every year.

Against this backdrop, the SDF is currently unable to meet its recruitment quotas. In 2025, it will have missed its target of 247,000 soldiers, with a general shortfall of more than 10 %, rising to 40 % among the lower ranks. With the demographic problem only set to worsen in the coming years, the 2022 strategic documents cite various measures to address it, such as raising the retirement age and improving pay and working conditions for the military. Japan is also relying increasingly on automation and artificial intelligence (AI) to reduce its staffing requirements. With an unemployment rate of less than 3 %, the demographic challenge affects not only the military, but also the administrative staff of the armed forces and the DTIB, which is competing with the rest of the private sector for high-level engineers. The third challenge is the relative weakness of the Japanese DTIB. In line with its restrictive defence posture, Japan has long prohibited military exports, particularly of lethal weapons. These restrictions have weighed heavily on Japanese defence companies. Relying solely on domestic demand, and earning only small profits, the Japanese arms industry has lost nearly a hundred companies since 2002. Although the restrictions have now been largely lifted as part of a general drive to revitalise the arms industry, Japan still lacks a strong industrial capacity in the military field, particularly when it comes to cutting-edge production. There are exceptions - Japan is currently developing new-generation combat aircraft with the UK and Italy and selling frigates to Australia - but the country remains on the whole dependent on imports, particularly from the United States. This dependence is not just a question of capabilities. Japan, through its strategic documents, now recognises that it cannot defend itself alone. Although there are certainly concerns in Japan - as elsewhere - about the reliability of US support since Donald Trump's return to the presidency and the publication of the new US security strategy, Tokyo remains heavily dependent on its military alliance with the United States: the only real alliance the country has. Unlike the North Atlantic Treaty Organisation (NATO), the Japan-US alliance is based on a fundamental asymmetry: the US is obliged to defend Japan, but not vice versa, with Japan only obliged to provide bases for the US military. Today, Japan is home to more American soldiers than any other country in the world, with around 55,000 garrisoned troops - particularly in ports and on large islands such as Okinawa. Initially intended as a deterrent to the Soviet Union, the American presence is now aimed at China and North Korea. Admittedly, the nature of the alliance is currently evolving as a result of Tokyo's rearmament, in the direction of a rebalancing of the roles of each party in the defence of Japanese territory. All the same, strategic autonomy is not a possibility in the short term. The United States is constantly encouraging Tokyo to invest even more in its own defence. In addition to the United States, Japan now cooperates with several countries that share its conception of international order. Tokyo, for example, has a «quasi-alliance» with Australia.^[6], With its strong strategic links with the Philippines and its increasingly important connections with NATO and some of its members, the country is one of the alliance's «global partners». These efforts to establish a network of partnerships are now making it possible to moderate, if only, the impact of the EU's economic policy.’as a minimum, dependence on the United States.

Outlook - A need for strategic diversification?

While the Japanese government plans to review its main strategic documents in 2026, the country is likely to continue to strengthen its defence posture in the coming years, with an increase in military spending and a greater search for strategic partnerships.

For the future, Japan has every interest in clarifying the responsibilities that it wishes to assume individually, and those that will certainly be shared in the event of a conflict in East Asia. At a time when Japan's military capabilities are increasing, Tokyo and Washington would also benefit from harmonising their defence policies, by endeavouring, for example, to define a joint command structure capable of meeting the requirements of a high-intensity conflict through the possession of interoperable forces. The fact that Japan now possesses offensive weapons means that the control of any escalation vis-à-vis China or North Korea will no longer be the sole responsibility of Washington, requiring greater Japanese-American coordination.

Today, Japan is showing no signs of distancing itself from the United States. The new government is clearly counting on full American support in the future, and thus seems, by strengthening its defence posture, to wish to present itself as a reliable partner. Paradoxically, the stronger Japan becomes, the more the United States may consider that disengagement is possible, as it would have less impact and run counter to Tokyo's primary strategic interests.

Faced with the risk of American disengagement, Japan has every interest in continuing to diversify its partnerships, notably with Australia and European countries. Beyond this diversification, autonomy in terms of conventional defence seems to be an imperative for Tokyo. In a scenario where the United States withdraws completely, and the other partners are unable to compensate for this, Japan would have no choice but to assume responsibility for its own defence. In such a case, a nagging question would inevitably arise for the country: as the only country in history to have used the atomic bomb, should Japan nevertheless acquire nuclear weapons?

[1] Embracing Arms: Securing Japan in a “New Era of Crisis” (International Crisis Group (ICG), 2025), 3

[2] Sebastian Maslow, «Make Japan Strong Again: Sanae Takaichi's Plan to Transform Her Country's Military», The Conversation, 17 February 2026

[3] Embracing Arms, 1

[4] Jingdong Yuan, «Japan's New Military Policies: Origins and Implications», Stockholm International Peace Research Institute (SIPRI), 2 February 2023

[5] Embracing Arms, 1

[6] Embracing Arms

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