The most striking thing to me in WWII is how as soon as Japan attacks the US at Pearl Harbor, they immediately gear up to destroy Germany. Rather than deal with Japan first and try to reach a peace treaty or territory agreement, they wanted to first and foremost stop Germany from being independent.
@Jonaschuzzlewit I don't know much of the details about it other than the fact that the FDR regime definitely wanted it to happen. Blockading Japanese oil and interfering with trade, as well as pulling the troops from Pearl Harbor right when it was going to happen so relatively few people died from it. Also notable is what happened with the Lusitania
I remember my total shock as a young person realizing that Pearl Harbor was purposefully allowed to happen. Watching Patton the movie led me to reading about him and that resulted in more questions than answers