Obama moved toward commanders in Iraq decision

This residual force will have a new mission, of training Iraqis, protecting U.S. assets and personnel, and conducting anti-terror operations. While those are technically noncombat tasks, the soldiers and Marines will remain in harm's way and engage at times in some form of fighting.

Understanding how Obama, his aides and his generals came to this plan must start with how the candidate arrived at his campaign promise.

Indeed, in the words of one administration official, there was never any magic to the 16-months time frame. At the time Obama first made the pledge, there were around 16 combat brigades in Iraq, and military experts told the candidate that Iraq was too fragile for a drawdown much faster than one combat brigade per month.

As early as last July, Obama gave the military leadership a strong signal that they could influence his thinking.

During a trip to Baghdad, Obama privately assured Gen. David Petraeus - then the top U.S. commander there - that although he favored a 16-month pullout, he would do nothing rash if elected to endanger security gains in Iraq, according to a U.S. official familiar with their meeting.

When he won, Obama and his team began meeting on the issue right away.

But the process didn't really begin until he held the reins of the presidency.

On Day One, Obama directed the Defense Department to start the planning for "a responsible military drawdown." Also that first week, he gathered top national security advisers in the Situation Room, with commanders participating in person and from the field via secure videoconference. A week later, he made his first trip to the Pentagon, to see the chairman and the vice chairman of the Joint Chiefs of Staff and all four uniformed service chiefs.

Multiple discussions with field commanders followed, as well as with Defense Secretary Robert Gates and Adm. Mike Mullen, chairman of the Joint Chiefs of Staff. Gates and Mullen presented Obama with three withdrawal options: one following his 16-month promise, one for a 19-month phase-out and another that stretched it over 23 months.

A dozen working groups were convened and 10 interagency meetings were held, said two White House officials. Another administration official said that while it was understood that the final decision resided in the West Wing, it was also clear to those outside the White House that they were being heard, with a lot of back-and-forth and draft-sharing.

The pivotal day was last Saturday, at an all-day National Security Council meeting. Three days later, Obama met with Gates at the White House, and met again on Wednesday with Mullen there with them. It was then that Obama formally accepted the 19-month option.

Obama officials insist that the potential political fallout played no role.

One reason was that presidential advisers calculated that whatever option Obama chose, even the most passionate in the anti-war camp would most remember that he ended the war — not when. Also, Obama entered office with the decision having been made much easier for him by none other than Bush, who struck a last-minute agreement with Iraqis requiring all U.S. troops, combat or otherwise, to be gone by December 2011.

So at most, Obama was talking about speeding up some parts of that by a year and a half. But that doesn't mean the president didn't face competing advice.

The service chiefs see Iraq as a drain on their resources and a strain on their personnel and their families. Top Marine commanders, for instance, preferred to concentrate their relatively small footprint on the new urgency in Afghanistan.

Gen. David McKiernan, the top U.S. commander there, has said that he needs not only additional combat troops but also surveillance aircraft and more civilian support. Obama's national security adviser, retired Marine Gen. James Jones, was already on record as supporting redirecting resources to Afghanistan. Meanwhile, Iraqi officials and some commanders, such as Gen. Ray Odierno, Petraeus' successor as the top U.S. general in Iraq, and outgoing Ambassador Ryan Crocker, pushed for the 23-month withdrawal plan. The two worried about keeping Iraq's modest momentum toward political reconciliation on track, particularly in light of the parliamentary elections set to be held in December. They didn't want to lose more than two of the 14 combat brigades now in Iraq before the end of this year.

Petraeus, now Odierno's boss as head of U.S. Central Command, is said to have leaned this way, too.

Odierno also wanted a backloaded withdrawal, and one without a rigid schedule in any case, because of the unpredictability of the situation around the elections. Gates said Friday that he and Mullen backed that approach.

"The president found that very compelling," said one of the White House officials.

In the end, that drove the strategy.

Gates said it would have been too much of a crunch to leave so many forces in place for the national elections and still meet Obama's original deadline of an exit by May.

So with the December elections as a starting point, the team added a two-month buffer requested by Odierno. The rest was logistics: how long would it take starting in February to get all the rest of the combat troops out safely? They settled on six months.

As Obama said on Friday: "We have forged hard-earned progress, we are leaving Iraq to its people, and we have begun the work of ending this war."