Commentary: Trump’s South Korea defence flip reminds Japan it has no Plan B

All of this may suit Takaichi very well, as Japan’s sense of beleaguerment intensifies. Since the start of her premiership, the argument for the country to start thinking more radically about its defence, and for the public to embrace the debate, has been repeatedly made for her by others. 

Almost from day one, China cast her as a re-militarisation-hungry fanatic in a way that has made Beijing look the more unreasonable. North Korea, meanwhile, has actively supported Russia against Ukraine while significantly escalating its anti-Japanese rhetoric, accusing Tokyo of fostering a “nuclear alliance” with South Korea and the US.

Earlier this month, Vladimir Putin paid his first-ever visit to one of four islands disputed between Russia and Japan, reviving Japan’s consciousness of another potential foe on its doorstep.

But the final, and perhaps most influential, card has now been played by Japan’s closest ally – not just through Trump’s Truth Social post, but the rapid erosion of norms that leaves nobody exactly sure how seriously to take his proclamations. 

The protesters outside Takaichi’s residence were a reminder of the constraints that have bound her predecessors from tampering with Plan A. August 2026 has reminded her how suddenly the public may demand a Plan B.