Sure, nationalism definitely serves that purpose. But please consider: in the most recent conflicts/flare-ups, the initiator has actually been Japan, not China. Their new female prime minister is an extreme-right-wing politician who is not only provoking China, but also picking fights with South Korea and Russia at the same time, while pushing aggressively anti-immigrant and exclusionary policies. Her approval ratings are also unusually high. It feels pretty strange that Japan gets zero criticism for this while all the focus stays on China.

Not strange at all. China is powerful, thus scary.

Ummm no… This is total fantasy.

Takaichi is a slightly right of centre nationalist. Pushing a mild tightening of some immigration rules to maintain the social contract around immigration, and fend off the right wing populists. Her policies amount to things like tightening foreign land ownership rules and refusing visa renewals for people not paying their health insurance or pension (which is mandatory by law for all residents).

She’s had friendly relations with SK so far and recently met with the SK President and bowed in respect to the Korean flag.

Her “provocation” of China was to state, when asked in parliament, that an armed invasion of Taiwan by China would be a case of a potential existential threat to Japan.

Which frankly is utterly obvious to anyone, including of course China. Japan hosts American military bases. If China attacked Taiwan, triggering an American repose then there would at the least be Chinese missiles aiming for Tokyo (Yokosuka) and Okinawa.