Now, Gen. David McKiernan isand he knows exactly where he's going to put them.
"I will use most of those forces in the southern part of Afghanistan," he said.
That's the heartland of the Taliban, where a hodgepodge of allied forces has been fighting what McKiernan says is at best a stalemate.
"Even with these additional forces, I have to tell you that 2009 is going to be a tough year," he said.
When the reinforcements hit the ground this spring and summer, the United States will have 55,000 troops in Afghanistan - and still, McKiernan wants more than that - upwards of 60,000. And he will probably get them later this year or next.
But whatever the number, says David Kilcullen, a former adviser to the American military, no guarantee of victory.
"I don't think we should kid ourselves that the chances of success here are, I would say, 50-50 at best," Kilcullen said.
The added troops will undoubtedly kill more Taliban, but in a war of counterinsurgency, the primary mission is not to kill the enemy, but protect the people.
"That's the one key task," Kilcullen said. "If we don't get that right, it doesn't matter. Whatever else we do will be useless, because we'll start losing the war."
The government of President Karzai also has to get it right and deliver services to its citizens. But a recent Pentagon report called the Afghan government "one of the weakest … in the world," which means the American buildup can not be a one-time surge, as it was in Iraq.
"For the next three-to-four years, I think we're going to need to stay heavily committed," McKiernan said.
Defense Secretary Robert Gates has said if that doesn't work, he would be very skeptical about putting in any more troops.
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