Imperial Japan was obviously a fascist state that needed to be dismantled (and sadly wasn’t nearly as much as it should have been), but if we’re talking barbarism, Pearl Harbor was nothing compared to the other items listed. It was an air strike on a naval base, nothing was really exceptional about it except that it’s rare for someone to dare to attack the US.
I’m pretty sure it was because someone dropped bombs on American soil. In any case, the fact that it touched on the American aggrievement fetish does not put it on par with the other events listed.