Generally, I am opposed to setting withdrawal dates in the place of mission complete statements, but since they won't be able to hold up their side of the bargain, maybe we should take them up on their offer:
Eleven Sunni insurgent groups have offered an immediate halt to all attacks — including those on American troops — if the United States agrees to withdraw foreign forces from Iraq in two years, insurgent and government officials told The Associated Press on Wednesday.
The again, if all insurgent attacks really did stop, my guess is that it wouldn't take two years for US forces to be largely out of Iraq.