Actually, none of the wars that you list were fought with the motives that you suggest. Maybe you should refrain from calling people idiots. :o)
Likewise, why we fought Germany after Japan attacked us is an interesting thing to discuss. But apart from the discussion, the fact remains: without American intervention a great many more Jews would have died in death camps created for the purpose of genocide.
And I will maintain that we went to Iraq for purposes of regime change. We went there to free 26 million Iraqis.
I hope your not sorry we did that.