Were you saying this to me? If that was the case, I did say that I do get the joke. I just dont' belive it's accurate.
When the Imperial Japanese Navy attacked the Pearl Harbor, they were clearly in alliance with the Nazi Germany. Also, they were taking over the world. Saddam did not possess that kind of threat. When the 9/11 attack occured, Al-Qaeda was responsible. The joke is implying that the U.S. was right to go after Iraq for something (mostly)Saudi terrorists did. Saddam Hussein's Regime was evil, no doubt about that. Only problem is, there are leaders like him all over the world. Weapons of mass destruction? It's not like Iraq was the only country suspected of possessing WMDs.
Now, if you had just said that Americans who didn't want to go against Nazis were foolish, I agree. On Iraq...... well, you know.