The violence against U.S. forces in Afghanistan has called into question the American exit strategy, which is set to play out steadily over the next three years.

It was only a few weeks ago that the second-ranking American military officer in Afghanistan laid out a new phase of that strategy. Small groups of U.S. advisers would team up with larger Afghan units to train them, said Lt. Gen. Curtis Scaparrotti.

The first of these U.S. assistance teams will head into Afghanistan this spring to train Afghan police and soldiers.

"As we move forward ... we're thinning our forces out, [and] these advisory teams will come in," said Scaparrotti. "You may see one [Afghan unit] that's got a [U.S.] rifle platoon with him because of the threat in the area and perhaps the proficiency of the unit they're with."

The threat the general was talking about was the Taliban. Now the threat appears to be from Afghan forces.

Consider what's happened in less than a week. American commanders have pulled U.S. military personnel from the Afghan government ministries after two American officers were murdered, allegedly by an Afghan official.

U.S. soldiers working with Afghans at bases around the country have been ordered to keep their distance. And security has been beefed up at operations centers where Americans and Afghans work together.

No Change In Strategy

U.S. Ambassador Ryan Crocker insists the heightened tensions do not mean a permanent split or any change in strategy.

"We remain committed to a partnership with the Afghan government and its people," Crocker told CNN.

Crocker pointed out that most Afghan forces are working closely with the Americans.

Kael Weston, a former State Department official who spent three years in Afghanistan, says the strategy of partnering with Afghans is working. And U.S. officials may have overreacted in separating Americans and Afghans.

"Most Afghans and most [U.S.] troops who are on the front lines live, eat and basically sleep together so I think there is that level of trust," he said.

Weston says that many deadly incidents are caused by cultural misunderstandings — like the recent burnings of several Qurans — rather than Taliban infiltration. And he says that the training teams are the best way to ease out the large numbers of American combat troops.

"I think it's crucial because after 11 years of war we need to start to transition and show the Afghan people that Afghans are protecting them," he said.

U.S. Advisers In Risky Places

John Nagl is a former Army officer and defense analyst who pressed for those American training teams. He says their small numbers and distance from home bases make them more vulnerable.

"I think that if we don't come to a reconciliation between the United States and the Afghan people that the strategy of sending small teams of American advisers from ministries to battalions is at real risk."

Nagl says Afghans are bitter that U.S. forces could be so culturally insensitive after so many years. American troops are angry they're being targeted by the very Afghans they're fighting and dying for.

Nagl says both Afghan and American officials are working to ease the situation, but the future is likely to hinge on the home front.

Some Republican presidential candidates have criticized President Obama for his apology over the Quran incident, says Nagl. And the attacks on U.S. forces could cause more members of Congress and a greater number of Americans to question whether the mission makes sense.

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