WASHINGTON - Seventeen months after President Barack Obama pledged to withdraw all combat brigades from Iraq by Sept. 1, 2010, he quietly abandoned that pledge Monday, admitting implicitly that such combat brigades would remain until the end of 2011.

Herson Blanco carries a mock coffin draped in an American flag during a protest march calling for an immediate end to the wars in Iraq and Afghanistan on March 2010 in Washington, DC. US public support for the Iraq and Afghan war and President Barack Obama's handing of the conflict has hit an all-time low after the leak of secret military documents, a poll showed Tuesday. (AFP/Brendan Hoffman) Obama declared in a speech to disabled U.S. veterans in Atlanta that "America's combat mission in Iraq" would end by the end of August, to be replaced by a mission of "supporting and training Iraqi security forces".

That statement was in line with the pledge he had made on Feb. 27, 2009, when he said, "Let me say this as plainly as I can: by Aug. 31, 2010, our combat mission in Iraq will end."

In the sentence preceding that pledge, however, he had said, "I have chosen a timeline that will remove our combat brigades over the next 18 months." Obama said nothing in his speech Monday about withdrawing "combat brigades" or "combat troops" from Iraq until the end of 2011.

Even the concept of "ending the U.S. combat mission" may be highly misleading, much like the concept of "withdrawing U.S. combat brigades" was in 2009.

Under the administration's definition of the concept, combat operations will continue after August 2010, but will be defined as the secondary role of U.S. forces in Iraq. The primary role will be to "advise and assist" Iraqi forces.

An official who spoke with IPS on condition that his statements would be attributed to a "senior administration official" acknowledged that the 50,000 U.S. troops remaining in Iraq beyond the deadline will have the same combat capabilities as the combat brigades that have been withdrawn.

The official also acknowledged that the troops will engage in some combat but suggested that the combat would be "mostly" for defensive purposes.

That language implied that there might be circumstances in which U.S. forces would carry out offensive operations as well.

IPS has learned, in fact, that the question of what kind of combat U.S. troops might become involved in depends in part on the Iraqi government, which will still be able to request offensive military actions by U.S. troops if it feels it necessary.

Obama's jettisoning of one of his key campaign promises and of a high-profile pledge early in his administration without explicit acknowledgment highlights the way in which language on national security policy can be manipulated for political benefit with the acquiescence of the news media.

Obama's apparent pledge of withdrawal of combat troops by the Sept. 1 deadline in his Feb. 27, 2009 speech generated headlines across the commercial news media. That allowed the administration to satisfy its anti-war Democratic Party base on a pivotal national security policy issue.

At the same time, however, it allowed Obama to back away from his campaign promise on Iraq withdrawal, and to signal to those political and bureaucratic forces backing a long- term military presence in Iraq that he had no intention of pulling out all combat troops at least until the end of 2011.

He could do so because the news media were inclined to let the apparent Obama withdrawal pledge stand as the dominant narrative line, even though the evidence indicated it was a falsehood.

Only a few days after the Obama speech, Secretary of Defense Robert Gates was more forthright about the policy. In an appearance on Meet the Press Mar. 1, 2009, Gates said the "transition force" remaining after Aug. 31, 2010 would have "a very different kind of mission", and that the units remaining in Iraq "will be characterized differently".

"They will be called advisory and assistance brigades," said Gates. "They won't be called combat brigades."

But "advisory and assistance brigades" were configured with the same combat capabilities as the "combat brigade teams" which had been the basic U.S. military unit of combat organization for six years, as IPS reported in March 20009.

Gates was thus signaling that the military solution to the problem of Obama's combat troop withdrawal pledge had been accepted by the White House.

That plan had been developed in late 2008 by Gen. David Petraeus, the CENTCOM chief, and Gen. Ray Odierno, the top commander in Iraq, who were determined to get Obama to abandon his pledge to withdraw all U.S. combat brigades from Iraq within 16 months of taking office.

They came up with the idea of "remissioning" - sticking a non-combat label on the combat brigade teams -- as a way for Obama to appear to be delivering on his campaign pledge while actually abandoning it.

The "remissioning" scheme was then presented to Obama by Gates and the chairman of the Joint Chiefs of Staff, Adm. Mike Mullen, in Chicago on Dec. 15, 2008, according a report in the New York Times three days later.

It was hardly a secret that the Obama administration was using the "remissioning" ploy to get around the political problem created by his acceding to military demands to maintain combat troops in Iraq for nearly three more years.

Despite the fact that the disparity between Obama's public declaration and the reality of the policy was an obvious and major political story, however, the news media - including the New York Times, which had carried multiple stories about the military's "remissioning" scheme - failed to report on it.

The "senior administration official" told IPS that Obama is still "committed to withdrawal of all U.S. forces by the end of 2011". That is the withdrawal deadline in the U.S.-Iraq withdrawal agreement of November 2008.

But the same military and Pentagon officials who prevailed on Obama to back down on his withdrawal pledge also have pressed in the past for continued U.S. military presence in Iraq beyond 2011, regardless of the U.S. withdrawal agreement with the Iraqi government.

In November 2008, after Obama's election, Gen. Odierno was asked by Washington Post correspondent Tom Ricks "what the U.S. military presence would look like around 2014 or 2015". Odierno said he "would like to see a ...force probably around 30,000 or so, 35,000", which would still be carrying out combat operations.

Last February, Odierno requested that a combat brigade be stationed in Kirkuk to avoid an outbreak of war involving Kurdish and Iraqi forces vying for the region's oil resources - and that it be openly labeled as such - according to Ricks.

In light of the fact that Obama had already agreed to Odierno's "remissioning" dodge, the only reason for such a request would be to lay the groundwork for keeping a brigade there beyond the 2011 withdrawal deadline.

Obama brushed off the proposal, according to Ricks, but it was unclear whether the reason was that Iraqi political negotiations over a new government were still ongoing.

In July, Odierno suggested that a U.N. peacekeeping force might be needed in Kirkuk after 2011, along with a hint that a continued U.S. presence there might be requested by the Iraqi government.

Gareth Porter is an investigative historian and journalist specializing in U.S. national security policy. The paperback edition of his latest book, "Perils of Dominance: Imbalance of Power and the Road to War in Vietnam", was published in 2006.