The agreement would allow not only military trainers to stay to build up the Afghan army and police, but also American special forces soldiers and air power to remain.
The prospect of such a deal has already been met with anger among Afghanistan’s neighbours including, publicly, Iran and, privately, Pakistan.
It also risks being rejected by the Taliban and derailing any attempt to coax them to the negotiating table, according to one senior member of Hamid Karzai’s peace council.
A withdrawal of American troops has already begun following an agreement to hand over security for the country to Kabul by the end of 2014.
But Afghans wary of being abandoned are keen to lock America into a longer partnership after the deadline. Many analysts also believe the American military would like to retain a presence close to Pakistan, Iran and China.
