I'll disagree with you Dred.
No one "did anything" about Hitler until he started operating aggressively outside Germany's borders. IE: the invasion of Poland. The reoccupation of the Rhineland, Czechoslovakia, Austria.. no world response.
No one "did anything" about Saddam, despite his internal slaughtering until he occupied Kuwait.
A nation's internal affairs are a nation's internal affairs, no matter how brutal those may be or how callous it may sound to ignore it. That's just the way it is.
We went this time on the assumption that Iraq's WMD posed a threat to US national security. That was the justification given. That is a legitimate justification IF indeed they had WMD that were actually a threat to us. I'll give them a little more time, but there still needs to be proof.