What an idiot, I don't even know where to begin, or why I should bother.
Let's begin with a map. To the east of Iraq is Iran. To the west of Afghanisan is Iran. Add that to Turkey, Pakistan, Saudi Arabia, Kuwait and the Persian Gulf, and Iran is nearly completely surrounded by US allies and semi-allies. If Iran acts up we can have support bases pretty much where we want.
As for not finding WMD... I am in the camp that they are they and buried. It will take decades to find them. Just as the Chinese are still finding Japanese chemical weapons 60 years after WW2.