[pigsty]

There’s a non-zero chance Russia pulls a Crimea and needs to defend Russian speakers in some remote region of Hokkaido, or starts seizing Japanese waters as their own. And that’s ignoring the islands Japan claims but Russia has controlled for decades.

This also sets a precedent for other neighbors. Korea claims random islands and politicians sometimes call for extreme actions to defend them from Japan (Japan does absolutely nothing and Japanese people, for the most part, do not know of the existence of these islands). China claims random islands that Japan controls with some of the more extreme factions saying Okinawa in its entirety isn’t legitimately Japanese, so it should be independent. But also Okinawa used to be somewhat subservient to China, so eventually independence would mean being a province of China, just like Russia is claiming with eastern Ukraine (or even all of Ukraine, depending on the day).

And there’s also Taiwan, which if China sees people get burnt out with the Ukraine war and go back to normal trade in a year, gives them pretty good odds to rain down missiles then rush in and seize the land with minimum international backfire. And if Taiwan is easily claimed, there’s no reason not to pursue Okinawa and South China Sea territories. And South Sea conflicts would screw over Japan as well, since there’s loads of trade with Vietnam and other countries in the region, and Japan is heavily dependent on food imports from China and elsewhere.

Japan has a lot of reasons to care. If Russia’s strategy pays off (and it’s unfortunately seeming like it will, since people outside of the region are getting burnt out on it and Russian mothers will happily fight until their last son is getting picked apart by dogs), those same methods will be used in East Asia.