2012 Troop Pullback Worries Military Experts

On Afghanistan’s battlefields, the most significant effect of President Obama’s latest orders will be felt at this time next year, when as many as 23,000 American troops who would have been on missions at the peak of the summer fighting season will instead be packing for home.

This will make it more difficult, if not impossible, military experts said, for the commanders to carry out one of their major goals for next year.

Senior officers said their military campaign plan for 2012 envisioned building on security gains earned by troops who had already flowed into Afghanistan’s south and southwest, with plans to turn some of those areas over to local forces. This would have freed American troops to pivot toward the vulnerable eastern border with Pakistan, but these forces may now be sent home.

Mr. Obama’s plan, announced Wednesday, has two stages. In the first, the United States will withdraw 10,000 troops by the end of this year, or about double what the military had desired. In the second, 20,000 additional troops, the remainder of the 2009 surge, will be withdrawn by the end of next summer.

His commanders can manage the first stage, according to a range of officers who are currently involved in the campaign or have served in Afghanistan. It would leave a substantial percentage of the surge force on the ground past the season when fighting traditionally slows in October and November as mountain passes freeze, preventing insurgents and supplies from traveling across the rugged borders from safe havens in Pakistan.

“Bringing 10,000 out by December is more than the military wanted, and quicker than the military wanted, but it is doable without any major impact on the ground plan this year,” said Lt. Gen. David W. Barno, who retired from the Army in 2006 after serving as the senior American commander in Afghanistan from 2003 to 2005.

“But putting a September 2012 expiration tag on the rest of the surge raises real concerns,” added General Barno, now a senior fellow at the Center for a New American Security, a policy research center. “That’s the middle of the fighting season.”

Michael O’Hanlon, a senior fellow at the Brookings Institution, another policy research center, said the September pullout date really means that many of those troops will stop carrying out their missions months earlier.

The president’s timetable, he said, “will require troops to spend most of the summer on the downsizing effort when they arguably should spend most of the summer fighting and taking away safe havens from extremists.”

Mr. O’Hanlon and General Barno said it was hard to fathom the military logic of setting a withdrawal deadline for the surge right in the middle of the fighting season. “This is a rushed ending to what has been a fairly effective surge,” Mr. O’Hanlon said.

Even after the withdrawal of the surge forces — an initial 30,000 plus 3,000 other support troops — the American presence in Afghanistan will be a considerable force of 68,000. But there will be less opportunity for carrying out the full counterinsurgency campaign planned by commanders. Afghanistan’s own security forces will number 300,000 by the end of the year, although questions about their professional ability remain.

Administration and Pentagon officials said Gen. David H. Petraeus, the commander in Afghanistan, had pressed for a less rapid withdrawal. Defense Secretary Robert M. Gates, who visited Afghanistan in recent weeks, also had warned against risking the success of the surge with a speedy withdrawal. But the president’s new order was preferable to even more accelerated proposals to withdraw all of the surge forces by early next summer.

In writing his campaign plan for Afghanistan, General Petraeus was said to have paid close attention to what the military calls “battlefield geometry,” which is the flexible shape, number and location of forces on the tactical map.

His plan would turn some security duties over to Afghan forces gradually, with American and allied troops stepping back from areas as they are pacified.