No matter who wins the presidential election, the United States is on its way out of Iraq. Senator Barack Obama offers the most specific and speediest withdrawal plan, but even Senator John McCain will not be able to keep a large number of combat troops there for long.

Without a major pullback from Iraq, the Pentagon will not have enough troops to fight in Afghanistan — where the United States is in danger of losing the real war on terrorism against Al Qaeda and the Taliban.

If that is not reason enough to begin serious preparations for a withdrawal, the Iraqis have decided that it’s time to scale back the American military presence. That’s the crux of a new security agreement that American and Iraqi officials say is nearly finished.

It would require American combat troops to leave Iraq by the end of 2011 unless Baghdad asks them to stay. That’s longer than Mr. Obama’s mid-2010 target but still the kind of finite framework that President Bush and Mr. McCain long opposed but are now being forced to accept.

We still do not know what Mr. McCain means with talk about some kind of magical “victory” in Iraq. Even American military commanders acknowledge that recent security gains are fragile. And there is no near-term expectation that Iraq can be the kind of stable democracy that Mr. Bush and Mr. McCain had envisioned.

What we do know is that only by setting a clear deadline and a sound withdrawal plan can America hope to keep encouraging Iraqis to make and implement the political reforms needed to stabilize the country. There is a lot to be done, and done quickly, to ensure that the withdrawal is safe, orderly and limits further damage to Iraq and its neighbors.

One of the most urgent tasks for the Bush administration is to ensure that Iraq’s Shiite-led government fulfills its commitment to integrate about 54,000 members of the Awakening Councils — Sunnis paid by the United States to provide security in local neighborhoods — into security and other government jobs.

The Sunnis’ 2006 decision to work with the Americans instead of attacking them has dealt a crippling, perhaps fatal blow to Al Qaeda in Iraq and is a major reason for the decline in violence.

Prime Minister Nuri Kamal al-Maliki and his allies have never trusted the councils and fear the Sunnis are just biding their time for a fight against the Shiites. Instead of trying to co-opt them, they are still looking for ways to defeat them — a very dangerous course.

Recently, the government arrested some Awakening Council leaders and balked at providing promised jobs to council members. For Iraq to function peacefully, all ethnic groups have to be part of the system.

The Iraqi Parliament, meanwhile, should be commended for finally approving a long-overdue law that paves the way for provincial elections by the end of January. Baghdad and Washington must make every effort to ensure the election is as free and fair as possible.

The elections will give a chance for participation in politics to tribal Sunnis and impoverished Shiites who previously opted out or were frozen out. But the elections also mean that some groups now in power may lose clout and may be tempted to return to violence. Emboldened by unconditional American support, Mr. Maliki has not shown enough interest in accommodating political rivals. Mr. Bush must insist that he work with other Iraqi leaders to ensure the election results are respected.

Lamentably, there is still no solution to a fierce dispute over the ethnically mixed, oil-rich city of Kirkuk — where provincial elections have been postponed until next year — or to the demand by Iraq’s Christians and other minorities for representation in government. There is still no law apportioning Iraq’s oil resources. Time is quickly running out for Washington and Baghdad to find answers. As The Times’s Alissa Rubin reported last week, there are still “scores to settle” in Iraq.