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.
Both Afghan and American officials said that they hoped to sign the pact before the Bonn Conference on Afghanistan in December. Barack Obama and Hamid Karzai agreed last week to escalate the negotiations and their national security advisers will meet in Washington in September.
Rangin Dadfar Spanta, Mr Karzai’s top security adviser, told The Daily Telegraph that “remarkable progress” had been made. US officials have said they would be disappointed if a deal could not be reached by December and that the majority of small print had been agreed.
Dr Spanta said a longer-term presence was crucial not only to build Afghan forces, but also to fight terrorism.
“If [the Americans] provide us weapons and equipment, they need facilities to bring that equipment,” he said. “If they train our police and soldiers, then those trainers will not be 10 or 20, they will be thousands.
“We know we will be confronted with international terrorists. 2014, is not the end of international terrorist networks and we have a common commitment to fight them. For this purpose also, the US needs facilities.”.....