The NAZIs were compelling Japan to put China on hold (know this from people that were there,) and attack Russia from the east. Russia's top spy in Japan was reporting to Stalin (maybe on purpose, instead of error,) that Japan was only interested in China. (Japan was... China to them had many incentives, Russia would be a costly, endless endeavor with minimal upside.)
The US had to get involved with Japan, to thwart this eventuality. The so-called conspiracy theories that the US enticed Japan to attack, are not theories at all, but facts. Of course, they miscalculated by keeping their ships too close together in Pearl Harbor making it too easy for Japan, which immediately roused the suspicion of many intelligent people in the US. At the time, Europe still had the opinion that the US didn't know how to fight, and we're only good for keeping Japan busy (and manufacturing equipment for the Lend Lease program.)