Stricter new rules for combat and bombing raids in Afghanistan may well complicate the battlefield for American forces, but officials say the changes are crucial to reducing civilian deaths that have been undermining the war effort.

Analysts say they do not expect the new guidelines to translate immediately to more peril for ground troops that depend on air support in battle, but if some combat encounters under the new rules lead to more dangers, the risk is worth the effort if it builds more Afghan support for the war.

“We are not in Afghanistan to make sure that fewer Americans die,” said Andrew Exum of the Washington think tank Center for a New American Security. “We are in Afghanistan to make sure fewer Afghan civilians die.” Gen. Stanley McChrystal, who took command of the eight-year-old war in Afghanistan last week, is expected soon to give US and NATO forces new guidelines on airstrikes, telling them to break away from fights with militants hiding in Afghan houses when they can.

McChrystal will issue orders within days saying troops may attack insurgents hiding in Afghan houses if the US or NATO forces are in imminent danger and must return fire, US military spokesman Rear Adm. Greg Smith said.

“But if there is a compound they’re taking fire from, and they can remove themselves from the area safely, without any undue danger to the forces, then that’s the option they should take,” Smith said. “Because in these compounds we know there are often civilians kept captive by the Taleban.” Though guidelines have been tightened before, the order would be one of the strongest measures taken by a US commander to protect the Afghan population.

Commanders and top Defense Department officials alike, say such deaths hurt their counterinsurgency mission because they turn average Afghans against the government and US and NATO forces.

The change probably will encourage Taleban and other insurgents to continue, or even increase, the practice of hiding among civilians and using them as human shields, Exum acknowledged. “But if they do that, then they’re going to lose the support of the population,” he said. Exum said the new guidelines probably will result in fewer airstrikes.

And that could limit the choices of ground troops who find themselves in a tough spot.

“This is going to constrain some of their options,” Exum said. “But the mission ultimately comes before the men, and I don’t think this is going to so (constrain them) that they are going to be subject to being overrun by the Taleban.” Lawrence Korb of the Washington think tank Center for American Progress, agreed, noting that there is a huge caveat in the new guidelines that should provide protection for the ground forces.

“If you’re in danger, you need to return fire, but if you can remove yourself without any due danger, that’s your option,” Korb said. “They will still have an out, but this amounts to telling pilots and forces to think again” about protecting civilians. “The question is not winning the battle, it’s winning the war,” Korb said.

Civilian casualties are a major source of friction between Afghan President Hamid Karzai and the United States.

According to the United Nations, NATO, US and Afghan forces killed 829 civilians in the Afghan war last year.

In the most recent instance, a May 4-5 battle between US and Afghan forces and militants in western Farah province killed dozens of civilians. A US report last week said US forces killed an estimated 26 civilians. However, Karzai’s government says 140 were killed, while an Afghan human rights group says the number is about 100.

Military forces had not made absolutely certain that civilians were not present, officials concluded. As much as setting new guidelines, McChrystal may also be setting a new tone.

“The important thing is not necessarily the individual guideline,” Exum said, but rather that McChrystal “is signaling new priorities in Afghanistan and signaling to his commanders” what those priorities should be.

“He is changing the operational culture in Afghanistan,” Exum said. “If it’s between killing the Taleban and saving civilians, you save the civilians.”