"I believe that each time we do that, we put our strategy in jeopardy," said Adm. Mike Mullen, chairman of the Joint Chiefs of Staff. "We cannot succeed ... in Afghanistan by killing Afghan civilians."
Mullen said additional forces and new tactics can help the United States turn a discouraging tide in Afghanistan. He said he was hopeful that "in the next 12 to 24 months, that we can stem the trends which have been going very badly in Afghanistan the last three years."
But speaking at the Brookings Institution, Mullen sounded frustrated that as the first of 21,000 U.S. reinforcements arrive, Taliban insurgents are having a seemingly easy time using American military prowess against them.
Mullen pointed to this month's disputed U.S. air strikes in Farah province, in which women and children were apparently among dozens of civilians killed. The United States says the Taliban is responsible for at least some of the deaths, but Mullen didn't spend much time defending U.S. actions.
The May 4-5 incident is still under investigation and Mullen indicated the details may always remain murky.
Afghans blame U.S. air strikes for the deaths and destruction in two villages in the western province. American officials say the Taliban held villagers hostage during the fight.
It is unclear exactly how many people died in the fighting. The Afghan government has paid out compensation to families for 140 dead, based on a list gathered from villagers. The U.S. military has said that figure is exaggerated, but it has not provided its own estimate.
If the Afghan toll is correct, it would be the largest case of civilian deaths since the 2001 U.S.-led invasion to oust the Taliban.
4615341"We've got to be very, very focused on making sure that we proceed deliberately, that we know who the enemy is," said Mullen (left, in a 2008 file photo). "The enemy uses this very effectively against us."
Mullen said it will take as long as two years for the United States to make full use of an extra 21,000 forces now moving into the country. He said he is encouraged that the first units arriving this spring seem to be off to a fast start.
"I would look to 2009 and 2010 to be incredibly important years in Afghanistan," Mullen said. "The violence level is up, the Taliban is much better organized than they were before."
Mullen also refused to rule out the use of unmanned drones, which the United States uses to target insurgent hideouts in both Afghanistan and Pakistan.
"We can't tie our troops' hands behind their backs," Mullen said.
By AP National Security Writer Anne Gearan