Mr Putin has provided a wake-up call for many of Japan’s dreamers. His unprovoked invasion of a neighbour is a reminder that autocratic regimes can be extremely dangerous. China’s recent sabre-rattling around Taiwan has highlighted the possibility that something similar could happen in Japan’s part of the world. “Ukraine today may be East Asia tomorrow,” Kishida Fumio, Japan’s prime minister, has repeated.

Politics is shifting as a result. Defence has jumped up the list of voters’ concerns, and permeated news agendas. Polling done earlier this year by the Asahi Shimbun, a liberal daily, found that 64% of Japanese favour strengthening their islands’ defences, the first time the figure has topped 60% since the paper began conducting the surveys in 2003. The Yomiuri Shimbun, its conservative rival, found 72% support for a stronger military; fewer than 10% felt that way in a similar survey carried out in 1988. Other polls show that a majority now favours acquiring long-range missiles which would let the sdf strike targets beyond Japan’s territory, another break from established norms. …

The Japanese government is due to release updated versions of its key national security documents, including the National Security Strategy (nss) and the National Defence Programme Guidelines, which inform foreign and defence policy for years at a stretch.

Those national security reviews were growing in importance even before Mr Putin’s latest invasion of Ukraine. The nss was first drafted in 2013. China under Xi Jinping has become more assertive and better armed since then. North Korea has advanced its nuclear programme. America has come to seem less reliable, especially during Donald Trump’s presidency. War in Ukraine has raised tension further still. “Our calculation has changed drastically,” says Otsuka Taku, who chairs the national security committee of Japan’s lower house. “We have to do more faster here.”