Yes there is a plan B

The LA Times reports that there is a Plan B for Iraq. You guessed it, it's cut and run.
Fallback strategy for Iraq: Train locals, draw down forces
If the current 'surge' fails, planners suggest relying on advisors as the U.S. did in El Salvador in the 1980s.

WASHINGTON — American military planners have begun plotting a fallback strategy for Iraq that includes a gradual withdrawal of forces and a renewed emphasis on training Iraqi fighters in case the current troop buildup fails or is derailed by Congress.

Such a strategy, based in part on the U.S. experience in El Salvador in the 1980s, is still in the early planning stages and would be adjusted to fit the outcome of the current surge in troop levels, according to military officials and Pentagon consultants who spoke on condition of anonymity when discussing future plans.

But a drawdown of forces would be in line with comments to Congress by Defense Secretary Robert M. Gates last month that if the "surge" fails, the backup plan would include moving troops "out of harm's way." Such a plan also would be close to recommendations of the Iraq Study Group, of which Gates was a member before his appointment as Defense Department chief.

If you think this sounds a lot like the recommendations of the Baker commission and many Democrats you would be correct. At least some in the Pentagon apparently realize much of the problem in Iraq is the large US presence.

"This part of the world has an allergy against foreign presence," said a senior Pentagon official, adding that chances of success with a large U.S. force may be diminishing. "You have a window of opportunity that is relatively short. Your ability to influence this with a large U.S. force eventually gets to the point that it is self-defeating."