Pentagon: No "Zero Option" for US Troop Levels in Afghanistan Post-2014

White House, meanwhile, still says a complete withdrawal is possible

The Pentagon said Tuesday it is offering no "zero option" for the number of troops that would remain in Afghanistan after the U.S. combat mission ends in December 2014. It said in a report to Congress that "substantial" long-term military support will be needed to ensure that Afghans can hold off the Taliban insurgency.

The White House has not ruled out leaving no troops behind after 2014, although officials say the most likely option is a residual training force of roughly 9,000.