Sometimes a war is justified, and coming to the aid of an ally getting invaded is a damn good justification.
Especially if that ally is simply asking for more hardware and not asking for feet on the ground.
Edit: Fixed the link, it was broken for some reason though it worked earlier today. IDK this mirror should work though
Fun history fact (any actual historians can correct me) Many of the Americans who were against war with Germany were sympathetic with Hitler's genocidal views or were straight up Nazis themselves.
20,000 American Nazis held a rally in Madison Square Garden. Facism was quite popular in the United States all the way til WW2 (and continued to be for 83 years afterwards).
somehow I'm not suprised