I don't think Saddam will become a threat again. He invaded Kuwait because he thought that the U.S. wouldn't get involved. He now knows that any aggressive action will be seen as a green light to bomb him into ash. He may be crazy, but he's not suicidal. I'd rather take the slight risk of inaction than the certain bloodbath of a war where one side is suspected of having WMD's and the other has declared their intention to use them if it feels they are necessary. If it really is necessary to eliminate Saddam, an assassination or airdrop invasion would have a much lower risk of large-scale WMD use than a land war.