WIREDGOV

Far from making a ‘reckless’ commitment likely to escalate tension, by checking Beijing’s hubristic tendencies, Japan’s Prime Minister Sanae Takaichi may have done us all a favour.

On 7 October 2025, Japan’s new Prime Minister Sanae Takaichi livened up a House of Representatives Budget Committee meeting with an unexpectedly revealing response to a question posed by opposition Constitutional Democratic Party of Japan (CDP) representative and former Foreign Minister Katsuya Okada. A few years before coming to office, Takaichi had spoken of a Taiwan situation having the potential to develop in a way that threatens Japanese citizens and might require a response by Japan’s Self-Defence Forces. What, Okada wondered, did she think now?

Precise Wording

‘A judgment must be made after comprehensively assessing all information in line with the individual and specific circumstances of what has actually occurred . . . A line of private ships from China surrounding Taiwan would not constitute such a situation. If it involves the use of warships and armed force, it would be a survival threatening situation no matter how you look at it’ Takaichi responded.

By using the clunky term ‘survival threatening situation’, the PM had invoked the legal formula that marks the threshold for Japan to activate its right of collective self-defence even if not attacked itself. This right had been denied in post-war Japan until new legislation in 2015, and it is a line that has not been crossed in the intervening decade.

This matters far beyond any controversies it causes in Japan or between Japan and China, because of the extent to which Japan’s response would determine how a conflict involving Taiwan unfolds. The credibility of US deterrence against a forcible change to Taiwan’s status quo depends on the US military’s ability to project and sustain force in the region. That in turn depends on a host of air bases and ports across Japan, especially the US Marines in Okinawa, and the 7th fleet in Yokosuka. A recent tabletop exercise the author attended on Taiwan and the Indo-Pacific, organised by Centre for Security Diplomacy and Strategy (CSDS) at the Vrije Universiteit Brussel, presents a plausible scenario of how a conflict might play out. Assuming it doesn’t go nuclear, a Sino-US conflict over Taiwan is likely to settle into a protracted struggle with the PRC unable to safely get a critical mass of troops across the straits, and US forces unable to break a Chinese ‘blockade by fire’ (using ground-based missiles to prevent shipping arriving in Taiwan). Following the initial clash, the US runs low on munitions, and Japan becomes the indispensable staging post for replenishment, for attempting to bring in supplies to sustain the population and resistance on Taiwan, and for imposing a counter-blockade on the PRC.

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