WASHINGTON — The killing of 16 civilians in Afghanistan, allegedly by a lone U.S. serviceman, is one more blow to President Barack Obama's hopes for an easy exit from a 10-year-old war.
The attack showed how horrific and unforeseen events in Afghanistan, not timetables and plans at the White House and Pentagon, are setting the endgame for America's involvement in a deeply unpopular war.
Washington had hoped for a carefully managed withdrawal starting this year, with 20,000 U.S. troops due home by September. Obama administration officials also are seeking a long-term security agreement with Afghan President Hamid Karzai in an effort to keep the Taliban insurgency at bay after the remaining U.S. and allied combat troops depart by the end of 2014.
In public, administration officials insisted that the mass slaying would not derail their plans or force them to reassess the withdrawal.
"This tragic incident does not reflect the commitment of the U.S. military to protect the Afghan people and help build a strong and stable Afghanistan," Defense Secretary Leon Panetta said in a statement Sunday.
But a series of setbacks have upset U.S. plans in recent months, and intensifies doubts in the White House about whether it is possible to salvage an outcome in Afghanistan that looks anything like the victory that Obama once promised.
The attack only makes the situation more difficult for Obama.
If he speeds up plans to withdraw U.S. troops, as polls show many Americans would like, he risks seeing the collapse of Afghan security forces, which are plagued by training problems and drug abuse. But slowing down the U.S. pullout would make it harder in an election year, when his Republican rivals have criticized his foreign policy record, to argue that he is achieving sufficient progress in Afghanistan.
A classified U.S. intelligence report based on interviews with captured Taliban insurgents concluded in January that the Taliban is biding its time until the U.S. and its allies withdraw. The report was leaked to the media last month.
The administration had hoped to use a NATO summit in Chicago in May to promote a strategic agreement with Karzai and the shift to an advisory role.
Michael O'Hanlon, director of research in foreign policy at the Brookings Institution, said the shooting will make it more difficult to negotiate a long-term partnership with Afghanistan. "These things have enduring significance," he said.