The commander of U.S. forces in the Middle East and Central Asia, General David Petraeus, says civilian casualties in Afghanistan undermine the U.S. and NATO military mission there. On Monday, U.S. troops fired on a passenger bus, killing four civilians and further stoking Afghan anger over civilian casualties by coalition forces.
Many Afghans are angry about the latest killing of civilians by U.S. troops. Hundreds took to the streets of Kandahar City, chanting "death to America."
Wounded passenger, Abdul Jabbar recalled the event.
"When we were close to the convoy of American forces, suddenly they opened fire at us," he said. "We were sleeping, then I don't know what happened."
It's the latest in a string of incidents in which coalition forces have fired on civilians perceived as threats. On Tuesday, U.S. General David Petraeus said such killings undermine the military's mission in Afghanistan.
"You cannot achieve your strategic goals, your strategic objectives, if tactical activities result in the loss of innocent civilian life," explained General Petraeus. "It undermines all that you are trying to do."
The top U.S. and NATO commander in Afghanistan, General Stanley McChrystal, has made reducing civilian casualties a priority, and they have declined in the past year. But battling insurgents is not always a clear cut fight
"In a conventional war achieving a mission involves accepting a personal risk," said McChrystal. "But if your mission is to take a hill, when your mission is over you know whether you have achieved it or not. In a counter-insurgency, by contrast, mission success is usually impossible to see…"
Stephen Biddle is a defense analyst with the Council on Foreign Relations in Washington.
"So you clear the insurgents out of a village and you patrol it a lot," said Biddle. "What do the villagers really think? Are they aligned with the government or not? How in the world do you know?"
Keeping civilian casualties to a minimum is critical now, say U.S. officials, as American troops prepare for a crucial offensive -- taking control of the Kandahar region, the spiritual home of the Taliban.
Biddle says that despite the protests, he thinks most Afghans want coalition forces and the Karzai government to succeed.
"The central advantage we have in Afghanistan is the unpopularity of the Taliban and what they are offering," explained Biddle. "The Taliban are a well-known quantity in Afghanistan and people have said consistently that they don't want it."