In interviews with U.S. Sens. Barack Obama, D-Ill., and John McCain, R-Ariz., the newspaper said the two diverge on how they see the importance of the U.S. mission there.

Obama said the invasion of Iraq was a mistake and the efforts he would make there are essentially a matter of damage limitation. He is advocating a fairly strict 16-month schedule for withdrawing U.S. combat brigades not dependent on political developments in Baghdad.

"If our benchmarks or conditions that we set are contingent on actions by the Iraqis and the Iraqis don't take them, then we are not in control of our own circumstances and our deployments," Obama told the Times.

McCain, however, says he sees Iraq as the "central front" in a larger struggle against terrorism.

"I'll continue to try to find ways to make them move forward. But to threaten withdrawal, frankly, is an option that I would be very reluctant to exercise unless I was sure that we had no other option, and I think we have lots of them," he told the newspaper.