Why? It was never proposed, prior to the invasion, that the US stay in Iraq indefinitely. If it was, please cite me the quote from the president or anyone else in authority.
We owe it to Iraq to stick it out at least until the final Constitution is written and the first post-Constitution elections are held.
Calling for a pullout even after this? What kind of a message does that send to the Brits? They knew this could happen if they helped in Iraq. They went anyway. You want to just cut and run now?