By Carlo Muñoz - 08/01/13 03:39 PM EDT
The immunity deal is part of a larger bilateral security agreement, the pact that lays the groundwork for a postwar American force.
Lack of an immunity deal for U.S. troops was a key factor in the failed attempt to set up a postwar security deal in Iraq and set the stage for the recent wave of sectarian violence against Iraqi forces and civilians in the country.
While work on a postwar deal for Afghanistan is largely complete, negotiators are awaiting final approval of the deal by Afghan President Hamid Karzai.
But fraying relations between Washington and the Karzai government have cast serious doubt over whether a postwar deal could be reached.
The Obama administration revived the “zero option” plan to leave no U.S. troops in the country after 2014 after a contentious meeting with Karzai in July.
However, top U.S. military leaders claimed they were not preparing for a zero option plan for postwar Afghanistan, saying such an outcome would be disastrous for Kabul and the White House.
"Anyone who reinforces this idea of December 2014 as being Y2K or a cliff that the Afghan people are going to fall off is actually being unhelpful," Gen. Joseph Dunford, the top U.S. commander in Afghanistan, said earlier this month.
"An option to me is something you plan against," he said. "And we are not planning against the zero option."
Roughly 32,000 American troops have already left Afghanistan, with the remaining 68,000 set to rotate out of the country over the next year and a half.
That final withdrawal, tentatively scheduled for next April, will officially end the American war in the country.