The same could happen if the deal is not signed in a timely manner.
Such was the case in Iraq, when the U.S. and Iraq couldn't agree on terms of a security arrangement.
Sectarian violence has plagued Iraq since, and some fear Afghanistan could follow that path without a continued U.S. presence if Afghan forces cannot defend the country themselves.
It was unclear if the mercurial Karzai would indeed wait for the elections or sign the agreement if approved by the Loya Jirga and the parliament.