Administration debate on pace of troop withdrawals from Afghanistan hinges on risk assessments

The debate over how many U.S. troops will remain in Afghanistan after 2014 comes down to risk.

Leaving too few troops in place could stall progress for Afghan security forces. But keeping too many troops there might prolong Afghanistan's dependence on the U.S. military and NATO.

A wrong calculation on troop levels could enable the Taliban and related groups to regain influence.

President Barack Obama has pledged to wind down the war and remove combat forces by the end of 2014. Members of Congress want to pull U.S. troops out faster.

Defense Secretary Leon Panetta says the post-2014 objectives should include fighting terrorists, training Afghan forces and providing logistical support. He isn't saying how many forces that requires, but analysts estimate as much as 10,000 to 15,000.