Whatever you think of Rep. John P. Murtha’s proposal for a prompt withdrawal of American troops from Iraq, it is clear that he has set the stage for a long overdue debate on the U.S. invasion and how best to bring it to an end.

He has made it clear that he wants American forces out of Iraq by the end of next year. In his resolution, deployment of U.S. forces in Iraq would be “hereby terminated,” and they would be “redeployed at the earliest practicable date” – not “immediately” as Republican leaders distorted its meaning in a one-sentence resolution that was overwhelmingly voted down, with Mr. Murtha among the nays.

He proposed deployment of a “quick-reaction force and an over-the-horizon presence of U.S. Marines” in the region, and that the United States would “pursue security and stability in Iraq through diplomacy.”

This position, by an influential Democratic congressman from Pennsylvania, a decorated Marine Corps combat veteran of the Korean and Vietnam wars, caught the Bush administration by surprise. Only last year, he had warned against premature withdrawal. But a recent visit to Iraq, where he spoke with senior officers and ordinary soldiers, convinced him that The war was “a flawed policy wrapped in an illusion.”

The Bush administration hammered him at first, with Vice President Dick Cheney growling that “the president and I cannot prevent certain politicians from losing their memory or their backbone.” Mr. Murtha cracked back with a reference to Mr. Cheney’s five military deferments.

But over the weekend Mr. Bush, in Beijing, shrewdly switched the response. He welcomed criticism and debate, praising Mr. Murtha as “a good man, who served our country with honor and distinction,” and rejecting slurs on his patriotism.

Mr. Murtha speaks for many senior officers in Iraq who have come to believe that the U.S. forces have become both a target and a stimulus for the insurgency. Gen. George W. Casey, commander of the forces in Iraq, has predicted fairly substantial reductions by early next year, assuming political and military progress. Privately, Mr. Murtha says many senior officers support his move.

John F. Burns, an old Iraq hand who has been covering the invasion from the start, wrote in The New York Times Sunday that out among the American troops “the no-timeline formula has undergone a subtle transformation, with commanders saying Iraqi units will only stand up when they see American units begin to stand down.” He went on: “American officers say they are confident that Iraqi units will withstand the many strains pulling at them – including sectarian loyalties and infiltration by insurgents – and allow the United States to hand over most combat tasks by the end of 2006.”

Thus, 2006 looks more and more like the long-awaited year of decision. And election day next November looks more and more like the date that Congress will prefer as it faces an electorate that has become increasingly suspicious of the original justification for war, worried about the daily carnage, and eager to see an end to American deaths there.