Col. Douglas Crissman told The New York Times that U.S. soldiers could become easy targets for insurgents when they begin their final draw down this summer and head for Kuwait.
Col. Crissman made the observation after rockets slammed into a military base in eastern Baghdad, killing five service members in the most deadly day for American forces since 2009.
"Our forces were attacked today, and we were just sitting still," Crissman said Monday. "What is going to happen to the threat when we line up our trucks to leave and start moving out of the country?"
In recent weeks insurgent fighters have stepped up their efforts to kill U.S. forces in what appears to be a strategy to press the United States to withdraw on schedule and not leave any troops in Iraq.
Commanders have fashioned an exit strategy which calls for the military to provide cash payments of $10,000 a month to 10 tribal leaders to hire workers to clear the roads, making it harder for militants to hide bombs.
To leave Iraq, 46,000 U.S. troops have to travel along a 160-mile stretch of road cutting through the desert and into Kuwait.
Col. Crissman said the insurgents are also trying to buy allegiance, intelligence and access.