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
prior to Pearl Harbor german warships had attacked 5 US navy vessels and over 100 US merchant marine vessels. the nazis declared war on the US 4 days after Pearl Harbor. the fact is that Nazi Germany was waging undeclared war on the US for the better part of a year, and indeed were the ones to formally declare war too. this is not an apt comparison to contemporary events.