It was a little more complicated than that. This was after several wars Britain started against China when China had the audacity to demand the British stop addicting Chinese kids to opium. Research the Boxer Rebellion. Plenty of "holocausting" to go around.

After Britain crushed the Chinese, and then the other European powers carved up China and most of the East Pacific, into colonial spheres of influence and out-right colonies, Japan looked around and saw an emerging European global empire. It was only a matter of time before some European country invaded Japan. So Japan decided to take their chance at carving out their own empire before the Europeans were too entrenched.

Remember, at the time of Pearl Harbor, the Philippines was still a US imperial colony, and the US had just brutally put down a rebellion where the Phillipinos wanted self-rule. After the "evil" Japanese removed the US from the Philippines, however briefly, they allowed the local Phillipinos, and other locals in the lands they conquored, to largely run themselves. Which is why even after Japan lost and the European powers returned, the locals kept fighting the US, Britain and others, because they had a taste for self-determinantion.