WASHINGTON - Barack Obama's order to halt US combat in Iraq marks a political promise kept?ray of light for a presidency clouded by economic blight, Afghan bloodshed and a likely Republican resurgence.

But his decision to highlight the pullout of combat troops as a milestone in a televised address?even as 50,000 of their comrades remain in a restive Iraq that lacks a stable government, is fraught with risks.

In statesman-like tones, Obama noticeably made no claims of clear-cut victory after a seven-year war he opposed, but did argue the sacrifices of US troops had forged a precious chance for Iraqis to chart their own future.

But his remarks seemed as much dictated by his parlous political position as by any pressing strategic or military need to mark the transition of the US Iraq mission from war fighting to training and counter-terrorism.

Obama's theme was that it was time to turn the page, from a grueling war in Iraq to rebuilding America's shattered economy and creating the jobs that will save a new generation's American dream.

He noted that as a presidential candidate he had promised to get US combat troops out of Iraq, and that he had delivered.

But exactly how that message will resonate remained unclear, given that Americans know that 50,000 troops remain in Iraq?and more than 104,000 US and NATO soldiers are in Afghanistan in a war Obama escalated.

"A lot of this is about politics and the desire to show that he has fulfilled another pledge," said Julian Zelizer, an expert on the politics of US foreign policy at Princeton University.

"I don't think it is very effective at all. Troops are still in Iraq... If you are still at war, you can't say you are not at war."

The risks of Obama's political position are apparent.

Some of those troops who will stay in the country until the end of next year will be engaged in counter-terrorism missions?so the risk of significant US casualties remains.

Others will help train Iraqi forces until they too leave in 16 months under a US-Iraqi agreement.

Should US soldiers suffer heavy casualties in a future attack, or be stuck in the middle if violence returns to Iraq, Americans will likely question Obama's leadership.

Meanwhile, events in Iraq still lack political clarity, and history's view of the tumult unleashed by the US invasion may not be known for years.

"The fact is... the US withdrawal is far from over, the Iraq war is not over, it is not 'won,'" said Anthony Cordesman of the Center for Strategic and International Studies in a new assessment of Iraqi security and politics.

"Any form of stable end state in Iraq is probably impossible before 2020."

Obama's address to Americans on Iraq made one thing clear?the profound decisions and compromises required of a commander-in-chief are more complex than the broadsides of a political candidate railing against "dumb wars."

Candidate Obama rode a tide of public anger over the Iraq war that helped deposit him in the Oval Office from where he addressed his fellow Americans Tuesday night.

But now President Obama is wearied and boxed in by two inherited wars: one in Iraq, which he opposed, another in Afghanistan he escalated, as well as the slowing recovery from the deepest economic crisis in generations.

He must walk a fine line between his liberal anti-war base, the sacred memory of troops who perished in Iraq and the complex demands of US security in a fractious world?all while facing a Republican backlash.

When his predecessor George W. Bush announced the war had begun?on March 19, 2003?from the same Oval Office, he declared: "no outcome but victory will be accepted."

Obama said that victory still needed to be earned, in an age without "surrender ceremonies," through the success of US partners and "the strength of our own nation."

So US combat in Iraq ended in a strange gray area, somewhere between victory and defeat, after seven and a half years in which 4,427 US troops died along with thousands of Iraqis.

For Obama, the speech also represented another step in a personal political journey dating from his famous anti-war speech as an unknown Illinois state legislator railing against the Bush administration in 2002.

In a 2007 congressional hearing, then-senator Obama lectured then-Iraq commander David Petraeus on the war, questioning the troop surge strategy hailed by Bush backers as the savior of the US mission in Iraq.

In a twist of historic irony, Obama this year placed much of his own political fate in the hands of Petraeus, as he turned to the talismanic general to implement his own surge?to save the war in Afghanistan.