Bush intended there to be a contingent of US Forces remaining in Iraq indefinately to guard against such as ISIS.
Obozo lost the war with his eagerness to claim the victory for himself by pulling out completely.
You're awfully nice to Obozo ..... Read up on PSD 11 (still secret) and Obozo's systematically throwing people to the jihadi wolves, and you'll see his motives in Iraq differently.
Iraq had to come apart, to make Obozo's story come together, that the US had lost a "war of choice" and that "it was Bush's fault". We were always going to lose, you see ..... Enlightened Dear Leader simply got us out just in time!
</off 'Rat hokum>