Not so wild when you realise that it's not the 1930s, and Japan isn't being led by an imperialist & expansionist regime. I'm not denying any past aggression from Japan, my grandparents fought them, but the situation is quite different now.
Japan is very much still jingoistic today, and Jingoism is what drove the Lugou bridge incident and the seconds sino-japanese war. While it was imperialism that drove the invasion of Korea and Manchuria in 1931, with a real need for resources and to give land and slave to industrialists, the 1937 war was totally dumbfuckery from jingoist sentiments. Basically Trump, but supported by 85% of the population.
That's why fascism doesn't work btw. They end up believing their own lies and do the most egregiously idiotic shit.
Based on historical and current events (USA) it takes roughly a couple of years for a country and its leaders to flip from pacifist to aggressive.