The United States has become an unreliable ally under President Donald Trump, challenging Japan to reconsider its 80 year old pacifist stance. Despite shifting public sentiment, the lack of the political leadership and commitment to its pacifist ideology limits constructive discussions about defence readiness in Japan.
On 22 February 2025, the United States stood against its allies by voting with Russia and North Korea against a Ukrainian amendment at the United Nations that called for Russia’s withdrawal from Ukraine. US President Donald Trump’s hostile policy became more apparent during Ukrainian President Volodymyr Zelensky’s visit to the US to sign a minerals deal, with the agreement cancelled following the televised confrontation between Trump and Zelensky. Since then, Trump has further criticised US allies, including singling out Japan for a lack of mutuality in the US–Japan Security Treaty.
This shift in attitude from the United States, Japan’s only security ally, leaves the country facing a wake-up call on defence. But Japan’s ability to change is limited by a lack of political leadership and its commitment to an outdated pacifist ideology.
Japan under Prime Minister Shigeru Ishiba outwardly stands with the G7 on the issue of Ukraine, continuing the policy of his predecessor Fumio Kishida who in 2023 became the first Japanese prime minister since the Second World War to visit a warzone. Japan has long insulated itself within its post-war bubble, as if such an act would somehow prevent the need to reassess its outdated military constraints.
Public support for Ukraine has not fallen below 75 per cent in Japan and the conflict may have influenced domestic sentiment towards defence. Opinion polls show that views towards constitutional revision of the pacifist Article 9 — which renounces the use of force to settle international disputes and sets limits on military capacity — have changed. But a willingness to specifically debate defence readiness is lacking, especially given that anti-militarism is now so deeply ingrained into societal norms and political doctrines. Choosing to avoid a difficult but necessary dialogue, Japan’s leaders have missed decades of opportunities to normalise the country’s defence posture.
To this day, Japan’s Self-Defense Forces (SDF) remain something of a social pariah, with many SDF personnel still reluctant to be seen wearing uniform in public. A primary school in Okinawa recently disinvited the Air Self-Defense Force band out of concerns that military symbols could cause anxiety among students and parents. Meanwhile, national universities continue to forbid military research, alleging that this would ‘threaten’ the ‘safety of society and peace’. More than a dozen universities restrict the acceptance of dual-use grants for military research.
Put simply, Japan’s refusal to contemplate anything more than incremental increases to its deterrence capabilities reflects an idealist mindset on national security even among the most highly educated. Japan remains stuck in its pacifist limbo, with a deep-rooted cultural ethos of wartime guilt serving as a normative constraint that largely precludes realistic discussion of the nation’s defence.
Article 9 may have assisted post-war Japan’s reintegration into the international community, but the Japan of the 21st century is very different to the Japan of the 1930s. While the Japanese public appears to have a covert realist view towards defence flexibility through constitutional revision, debating actionable steps that would improve security and deterrence still appears a step too far. Many still believe that sitting out conflicts is a moral position, citing and hiding behind Article 9. Only in Japan is such a unilateral pacifism widely considered viable.
This incongruent contradiction of simultaneously appreciating and ignoring threats has been maintained with relative ease given the US–Japan Security Agreement, under which the United States is obliged to defend Japan. The US has also deployed its most advanced military assets to Japan. But this hitherto trustworthy partner has suddenly become unreliable.
If Trump’s complaints about the US–Japan Security Agreement are matched by action and the United States makes substantial withdrawals from Japan, this would be a huge burden to Japan’s defence and upset the delicate status quo over Taiwan. Russia has also asserted that Japan increasing its security is a risk in the region, mirroring the rhetoric that identified NATO as the genesis of the Ukraine conflict.
Still, Ishiba appears detached and unable to act on these critical issues. Asked about Trump and Zelensky, he expressed hope that both leaders would employ ‘diplomacy backed by compassion’ and stated he has ‘no intention of taking sides’.
Those who assume that the Ukraine conflict is distant think simplistically in terms of geography, not in terms of US willingness to defend democratic norms. Yet to those capable of thinking holistically about the nature of collective self-defence, it has become abundantly clear that the threats to Asia’s volatile peace have multiplied exponentially in just three months. The world is becoming more unstable, uncertain and dangerous.
Japan is a unique test case, as it is not part of a collective economic or defence ecosystem like the EU or NATO. Instead, it is intrinsically interlinked and interwoven with the United States. Unlike Europe, Japan does not yet seem to comprehend the serious nature of US security protection potentially being impaired. Unless this changes, the result is likely to be yet another missed opportunity for Japan to seriously reconsider its national defence.