Tokyo’s Taiwan Tightrope

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The recent row between Japanese Prime Minister (PM) Sanae Takaichi’s new government and Taiwan-obsessed messaging from Beijing marks more than a diplomatic spat. In early November 2025, PM Takaichi told Japan’s parliament that a Chinese military blockade or use of force around Taiwan “could by all means become a situation threatening [Japan’s] survival,” thereby invoking the legal standard in Japan’s 2015 security legislation that would allow the Japan Self-Defence Forces (JSDF) to act in “collective self-defence.” Beijing’s response unsurprisingly was sharp but unreasonably crude. The Chinese consul-general in Osaka posted (and later deleted) a social media message stating roughly: “the dirty neck that sticks itself in must be cut off,” prompting Tokyo to file a formal protest. Beijing’s undiplomatic language underscores its reactiveness to any external commentary on what it deems a core strategic interest. China’s foreign ministry accused Japan of violating the 1972 Communique and demanded Tokyo cease interfering in China’s “internal affairs.” 

This episode highlights the inherent tension in Japan’s own strategic posture, a nation deeply anxious about its security environment yet bound by constitutional and diplomatic restraints.

This episode highlights the inherent tension in Japan’s own strategic posture, a nation deeply anxious about its security environment yet bound by constitutional and diplomatic restraints. While Tokyo views developments around Taiwan as directly affecting its national survival, its ability to respond remains circumscribed by Article 9 of the Constitution, which renounces war, and by the commitments made under the 1972 Joint Communique with China. This dichotomy, between the imperatives of deterrence and the constraints of pacifism, lies at the heart of debates surrounding the role, scope, and evolution of the JSDF. Nonetheless, it is also vital to note that Tokyo has been increasingly cognisant of security in and around the Taiwan Strait in what it considers crucial to its own national security.

From Tokyo’s vantage point, Takaichi’s remarks are rooted in strategic realism. Japan’s southwestern archipelagic geography places it on the front line of any Taiwan Strait contingency, with the island of Yonaguni lying only about 110 km from Taiwan. A Chinese naval blockade or narrowing of the United States’ (US) access to the Philippine Sea could immediately impact Japan’s access to forward basing and sea lines of communication, imposing existential risk to Japanese national survival under the constitutional interpretation underpinning the 2015 law. Takaichi’s invocation of a “survival-threatening situation” is not unfounded; Tokyo is publicly clarifying that the Taiwan contingency is not someone else’s problem, but a core Japanese security concern.

However, while Takaichi later described her remarks as “hypothetical,” Tokyo constraints also include economic interdependence with China in addition to constitutional pacifism and a broader regional posture that prizes stability. This is evident in Japan’s Chief Cabinet Secretary Minoru Kihara's response on the issue, where he reaffirmed Tokyo’s adherence to the 1972 Sino-Japanese Joint Communique, which recognises the People’s Republic of China as the sole legitimate government. Kihara emphasised that Japan’s position on Taiwan remains unchanged and that Tokyo continues to expect cross-strait issues to be settled peacefully through dialogue. His statement sought to alleviate tensions by balancing Japan’s legal and diplomatic commitments with its growing security concerns, indicating Tokyo’s intent to avoid escalation while maintaining a principled stance on regional stability and peace.

This context underscores the evolution of Tokyo’s security framework, from the establishment of the Self-Defence Forces to the constitutional reinterpretation that expanded the nation’s capacity for collective self-defence. In 1954, Japan created the Self-Defence Forces (SDF) with the sole mandate of protecting the nation from external threats. To define the scope of this right, successive governments outlined three conditions under which Japan may exercise self-defence: first, when the country faces an imminent and unlawful act of aggression; second, when no other means are available to avert the threat; and third, when the use of force is strictly limited to the minimum necessary level. At the start of his second term, former PM Shinzo Abe established a commission to examine Japan’s interpretation of Article 9. Its 2014 report proposed allowing broader collective self-defence. After negotiations, Abe’s cabinet approved a reinterpretation on 1 July 2014. While retaining the original three conditions for self-defence, the change allowed Japan to use force to aid partners if an attack on them in turn threatened Japan’s own survival or the fundamental rights of its citizens. The 2014 reinterpretation marked a watershed, enabling limited collective defence while maintaining the constitutional principle of using force only as a last resort.

This dichotomy, between the imperatives of deterrence and the constraints of pacifism, lies at the heart of debates surrounding the role, scope, and evolution of the JSDF.

Tokyo should sustain its deterrence message but calibrate public diplomacy accordingly. Tokyo must also widen its defence-industrial base, deepen interoperability with the US, Australia, the Association of Southeast Asian Nations (ASEAN) partners, and strategically align its Taiwan contingency posture with broader Indo-Pacific resilience (including Japanese–Indian maritime cooperation). For India, this moment underscores the merit of aligning with Japan’s security thinking not by entering conflict footprints in Taiwan but by reinforcing regional maritime capabilities, logistics linkages, and shared deterrence frameworks in the Indo-Pacific.

Japan’s strategic posture toward a possible Taiwan contingency is grounded in geography and realism. The southwestern Japanese islands lie just a short distance from Taiwan, placing Japan’s national security on the front line of any cross-strait disruption. A crisis in the Taiwan Strait would threaten sea lanes in the Philippine Sea, vital communications cables and supply routes, and Japan’s access to forward basing, all of which are consequences Tokyo views as directly affecting its survival. Accordingly, remarks by Japanese leadership linking Taiwan’s fate to Japan’s self-defence framework are not anomalies, but extensions of an ongoing doctrinal shift. Tokyo has increasingly framed stability in the Taiwan Strait as indispensable for its own national security. It is investing in its outlying island defences and maritime posture to reflect that logic. Japan’s move toward explicit concern over a Taiwan contingency reflects the imperative that ambiguity in such a scenario may no longer be tenable. This recent row is therefore not merely a rhetorical flare-up but a marker of the increasingly tenuous regional geopolitical scenario. 

Pratnashree Basu is an Associate Fellow at the Observer Research Foundation.

• International Affairs
• East Asia
• china taiwan conflict
• china taiwan relations
• Japan china relations
• japan china tension over Taiwan
• japan military deployment to Taiwan
• japan self defence forces
• japan taiwan relations
• sino japanese joint declaration

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