The rising sun: Japanese remilitarisation in Trumpian context 

For over eight decades now, Japan has been one of America’s most stalwart allies. Previously used as a launch site for landing in the Korean War, America now has 55,000 soldiers stationed on the Japanese islands. Japan has also avoided the serious military and political rifts with the US that even the UK had weathered (with the Suez Crisis) during the economic tensions that arose in the 1980s. Yet with Trump forcing his allies to question previously ironclad commitments to US internationalism, Japan must finally reckon with its ‘nominal’ commitment to pacifism and self-defence. 

Even before President Trump’s second term, Japan had been seeking to end their reliance on the US. However, the threat of China remains too large to tackle without US intervention and aid, so Japan must thus follow a cautious line between the rocks of Chinese power and Trumpian transactionalism. The US’s 2022 National Security Strategy, adopted under President Biden, reflected deep anxieties about China’s rise and long-term doubts about US commitment, regardless of who occupied the White House. Trump’s second term has catalysed those anxieties and accelerated their implementation, forcing Japan to navigate between deterring China and satisfying Trump’s demands for burden-sharing. 

The rise of China as a superpower in East Asia was inevitably going to create tensions with their Japanese neighbours. Militarily, the Chinese navy is the world’s largest by the number vessels, and their economy has continued to rise, most prominently in fields formerly dominated by Japan, like manufacturing. Geographically, tensions are erupting on two fronts: they clash on the contested Senkaku/Diaoyu Islands, and in the South China Sea where increased Chinese presence, with artificial atolls and outposts, threatens the shipping route to Japan, upon which Japan relies for 80% of its oil supply. 

Beyond these structural concerns, tensions are inflamed by the complex history between the two nations, especially around the Second World War and Japanese crimes perpetrated towards China. Even as anti-Japanese grievances are exploited by the CCP to promote domestic unity and nationalism, China still poses a very real threat to what Japan prefers to be the equal balance of power in the region. Under President Biden, the threat of China was significant enough to force the US’s reconsideration of Japanese pacifism, but with Trump’s self-interested foreign policy (events in Iran have shown Trump is not an isolationist), the shift must be accelerated to backstop the US’s absence in East Asia.

If China were to seize Taiwan and/or the surrounding shipping lanes, it would constitute a situation in which Japan’s military could respond forcefully

Since President Trump’s inauguration, Japan has accelerated their remilitarisation – both in capability, with the deployment of Type-12 missiles in March 2026 and the SHIELD system (unmanned coastal defence) planned for March 2028, but also in rhetoric. In an address to the Diet (Japanese Parliament), PM Takaichi announced that if China were to seize Taiwan, and/or the surrounding shipping lanes, it would constitute a situation in which Japan’s military could respond forcefully. Even the mere utterance of a potential wielding of Japanese force illustrates the scale of change taking place in the region. 

As previously mentioned, the Japanese policy for its military expansion is laid out in the 2022 National Security Strategy. In the context of the rise of China and a nuclear North Korea, the strategy indicates a complete reversal of the previous approach of pacifism, with a key emphasis on strike capability. Alert to the weakening missile balance, Japan seeks not only to boost its own missile defence capability, thought to be 60% sufficient, but also to enable, for the first time, the acquisition of offensive capabilities against Chinese targets.

Chinese state media has decried the policy as pursuing ‘neo-miliarism’, and there remains the risk that Japanese reconsideration will provoke an arms race between Japan and China

This strategy has been put into action by the Japanese acquisition of 400+ Tomahawk cruise missiles, F-35 stealth fighters, and Aegis destroyers. Conventional warfare is to be joined by increased focus and investment in the ‘Usaden’ (宇サ電) sphere (space, cyber, and electromagnetic warfare domains). The Japanese Air Self-Defense Force will begin the operation of space-based optical telescopes and the Japan Ground Self-Defense Force (JGSDF) will play a central role in expanding infrastructure and developing necessary human resources.  

There are, of course, difficulties with this. Japan has not just by its innate nature remained pacifist since 1945, but also by a rigid constitutional structure. Article 9 of the Japanese Constitution forbids the use of war to settle international disputes. Whilse there is broad support for increased military spending, questions of constitutional revision are still divisive, with governments currently relying on a policy of ‘collective self-defence’. While rearmament remains broadly popular, indeed, the removal of Article 9 remains much more contested, with no majority for revision. 

Externally, how will other nations react to this policy? Chinese state media has decried the policy as pursuing ‘neo-militarism’ and there remains the risk that Japanese reconsideration will provoke an arms race between Japan and China, escalating the stakes and binding the nations into more hostile relations, hurtling towards active conflict. Indeed, China is escalating its military posturing against Japan. On December 6, 2025, Chinese jets locked control radars onto Japanese fighters near Okinawa. That same month, China mobilised over 100 naval and coast guard vessels from the Yellow Sea to the Western Pacific in its largest maritime show of force to date, a demonstration of China’s willingness to isolate and confront Japan and Taiwan simultaneously. 

Most crucially, however, is the reaction of the White House. Japan knows that even with the alliance of other regional powers in the Pacific, from ASEAN to South Korea, and to Australia, it would likely be unable to prevent a Chinese invasion of Taiwan. This event would most likely to spark the two nations into an all-out war. As the exit passage of the South China Sea, ensuring free transit through the Taiwan Strait as well as preventing a Chinese takeover of the island acts as a fundamental strategic imperative for Japan to defend Taiwan. Thus, the US must be brought onside and have its commitment to East Asia firmly reiterated and the defence of Japan ensured. In a recent visit to the White House by the Japanese PM, President Trump, whilst joking about Pearl Harbor, praised Japan for “stepping up to the plate”. His logic has always seemed simple; he is not an isolationist, but a transactional force, almost mercenary in his fixation on financial contributions. 

Japan finds itself in the unenviable position of having to deter China and affirm Trump’s transactionalism; yet not so doggedly as to draw itself into an unwinnable arms race against China

Rather than principles and alliances, the President seems to support the wars he perceives as eminently winnable. During his first term, he repeatedly called on NATO nations to increase spending, or else the US would withdraw and let Russia do “whatever the hell they want”. And so, the aim in Japan seems to be to improve its own defence capabilities, while dispelling President Trump’s anxieties that common defence is a zero-sum game for the US. It aims to do something, but more crucially, it aims to be seen as doing something.  

Despite these efforts, Japanese defence officials will likely be concerned by the recent US defence policy signals. The 2026 US National Defense Strategy institutes US homeland defence as the highest priority, not Europe, and definitely not East Asia. In light of this shift to US isolationism, allies are expected to receive “critical but limited” support as part of the US’ desire to project strength, but not invoke confrontation. Most concerning is the complete omission of Taiwan from their strategy. Taiwanese officials may hope Takaichi’s justification of hypothetical force is dependable. The question remains to be seen whether Japan (or other East Asian nations collectively) will respond to Chinese incursions on Taiwan without explicit assurances of US backing. 

Japan finds itself in the unenviable position of having to deter China and affirm Trump’s transactionalism, yet not so doggedly as to draw itself into an unwinnable arms race against China. The needle they thread is impossibly narrow. 2022’s National Security Strategy suggests Japan’s bet may be achievable. However, one must always reckon with the possibility that Trump, wounded by an ongoing intervention in Iran, will reaffirm his transactional isolationist calculus. 

Japan would be left with few palatable options. Allying with ASEAN in an eastern NATO equivalent could be possible, but it’s unlikely to decisively deter Chinese ambitions. In another scenario, Japan could become the only nation to have experienced the horror of nuclear weapons, only to subsequently acquire them in their defence armoury, a possibility some LDP members have already floated. The 2022 National Security Strategy wagered that Japan could thread this needle. Trump’s war in Iran, China’s commitment to unification with Taiwan, and the 2026 NDS suggest that this wager may have been catastrophically optimistic.