And the winner is ... Iran

Historians may conclude that the U.S. in 2003 invaded a dysfunctional, decaying, sanction-ridden Iraq over weapons of mass destruction that weren't there any more and that Hussein might never have been able to reconstitute, while helping establish the conditions for Iranian dominance of Persian Gulf:

( Iranian hardliners cultivate influence in post-Baathist Iraq, aspire to nuclear weapons, and the U.S. may lack the means to curb the growth of Iran's regional power )