Barack Obama's new position on Iraq, which turns out to be the same as his old position, is disappointing. It's too confining, leaving too little room to adjust to changing conditions.

Early last year, when the war was at its worst, Obama said he would withdraw U.S. troops within 16 months of becoming president. The Democrat set this timetable partly because, he said, the American military could not referee a civil war between Sunni and Shiite Muslims.

Since then, President Bush ordered more troops to Iraq. This "surge," coupled with a strategy of turning Sunnis against foreign al-Qaeda fighters, has succeeded in reducing violence.

It's too soon to tell if this relative stability is temporary or the permanent foundation for a healthy society. Civilian leaders have not yet seized this opportunity to strengthen their young central government, nor is the Iraqi military fully capable of standing on its own. But the surge of U.S. troops at least has created conditions that make these goals more possible.

Given the improved conditions in Iraq, there had been speculation that Obama would modify his specific timetable for withdrawal. The candidate himself suggested in recent weeks that he was "refining" his plan. He said he would consult with military commanders on the ground.

But on Tuesday, before his upcoming trip to Iraq, Obama reiterated his plans to withdraw all troops within 16 months. "True success will take place when we leave Iraq to a government that is taking responsibility for its future," he said.

The next president's goal should be to remove U.S. troops from Iraq as soon as possible, consistent with protecting those troops and serving U.S. security interests. But Obama's adherence to a timetable that helped him to win his party's nomination seems more calculated to reassure his political base, rather than to adapt policy to changing conditions in the war. If he intends to consult with military advisers, why announce he's sticking to a precise timetable offered last year?

To his credit, Obama recognizes the renewed threat in Afghanistan, and proposed sending about 7,000 troops there. He presented a realistic, determined plan for confronting the Taliban and al-Qaeda forces in Afghanistan and Pakistan. John McCain, the likely Republican nominee, would deploy about 10,000 troops to that troubled region.

Thus the campaign is presenting voters with a sobering choice: a war with one front, or two. McCain proposes to keep troops in Iraq longer than Obama would; the Arizona Republican intends to bring most soldiers home by 2013. Under Obama's schedule, nearly all troops would be withdrawn from Iraq by the summer of 2010, seven years after the war began.

If there is cause for optimism in these scenarios, it's that there is already momentum for bringing more troops home from Iraq. Bush has withdrawn five brigades from Iraq this year. The end of so costly a military presence is more easily contemplated than it was a year ago; the debate is increasingly focused on how rapidly to bring it to a conclusion.