The 149,000 U.S. troops currently in Iraq are increasingly part of the problem, they say.
During a trip to Washington, the generals said the presence of U.S. forces was fueling the insurgency, fostering an undesirable dependency on U.S. troops among the nascent Iraqi armed forces and energizing terrorists across the Middle East.
Officials backtracked on their expectations of what the U.S. military can achieve in Iraq months ago. But this week's comments showed that commanders believe a large U.S. force in Iraq might in fact be creating problems as well as solutions.
"This has been hinted at before, but it's a big shift for them to be saying that publicly," Michael O'Hanlon of the Brookings Institution in Washington told the Los Angeles Times.
2014: The Year in Music [PHOTOS]