After previously suggesting that some American forces could remain in Afghanistan for decades to come, the Pentagon says it's considering the possibility that no U.S. forces could be stationed there after 2014. NATO and American forces are planning to withdraw all combat troops from the country by the end of next year, but its been widely assumed that some would remain to assist the still-wobbly Afghan army with training and security, as well as anti-terrorist missions.

However, during a press conference on Tuesday, Deputy National Security Adviser Ben Rhodes became the first Obama administration official to raise the possibility of a complete withdraw. Rhodes says the Pentagon is considering a range of options, including keeping any where between 6,000 and 15,000 U.S. soldiers on the ground at all times. There are currently about 66,000 troops in the country now, down from a peak for more 100,000 at the height of the 11-year-old war.

The determining factor appears to be the need to fight al-Qaeda terrorists, who have mostly been driven to other nations, like Pakistan and Yemen. However, Pakistani-based terrorist groups routinely cross the border to attack American forces and remote villages and without a base of operations in Afghanistan, striking back at them with anything other than a drone becomes nearly impossible.

Of course, the talk may also just be that: talk. Afghan President Hamid Karzai is coming to Washington on Friday to meet with Barack Obama and the White House may simply be trying to turn on the pressure before any negotiations on troop status take place. Karzai has asked for U.S. troops to remain beyond 2014, but the Americans want more legal protections for their soldiers and have also tried push the Afghan army to become a more reliable fighting force. There's also the issue of "green on blue" violence that has seen "friendly" Afghan soldiers (or terrorists who have infiltrated the army) inflicting more casualties on Western troops than any enemy has.