WASHINGTON - Having learned the limits of force in Iraq and Afghanistan, US military strategists are rewriting decades-old military doctrine to place humanitarian missions on par with combat, part of a new effort to win over distrustful foreign populations and enlist new global allies, according to top commanders and Pentagon officials.

The Defense Department is implementing a series of new directives to use the American arsenal for more peaceful purposes even as it prepares for war, including a little-noticed revision this year to a document called "Joint Operations," described as the "very core" of how the military branches should be organized.

The effort illustrates a growing recognition that, to combat radical ideologies and avert future wars, the Pentagon must draw more heavily on its deep reserves of so-called soft power - its ability to set up medical clinics in a remote part of the world, for example - to balance the more traditional "hard power" of military force, according to more than a dozen US military officers in several regions of the world and planners inside the Pentagon.

"Things have changed significantly," Jerry Lynes, a retired Marine Corps colonel who is now chief of education and doctrine for the Joint Chiefs of Staff, said in an interview. "We have taken our traditional principles of war and added to them."

The changes have already translated into new military operations. When a US military team arrived by helicopter in Cambodia's rural Kampong Chhnang Province in late May, the imam from the local mosque spread the word and hundreds of locals descended on the Americans.

But it was not confrontation they sought. It was free healthcare. The Friendship Clinic, offering primary and vision care, dentistry, a women's health center, and medical training, was part of a first-of-its kind humanitarian mission called Pacific Angel by the Honolulu-based 13th Air Force.

In recent months, Navy war ships have been dispatched to some of the poorest nations to administer medical aid, the Air Force is flying regular humanitarian flights, and teams of US military personnel are helping rebuild schools in Latin America.

But while the change in emphasis is generally accepted as a positive development, some are also warning that the military risks taking on nonmilitary missions that should be the purview of the State Department and other civilian agencies.

Secretary of Defense Robert M. Gates, who has called for greater emphasis on diplomatic and economic tools to further American interests, warned in a speech this month about the "militarization" of American foreign policy and repeated his calls for building new civilian capacity for strengthening fragile states.

Others have also cautioned against using the military to perform jobs better suited to civilians, such as democracy building and development aid.

"Our [foreign] policy is out of whack," said Kenneth Bacon, a former assistant secretary of defense who now runs Refugees International, a nonprofit organization. "It is too dominated by the military and we have too little civilian capacity."

Bacon is particularly concerned about Pentagon plans for a new US Africa Command. In a report published this month, Refugees International called on the next administration to limit the military's role in Africa to conducting security-related tasks, such as training foreign militaries and providing critical humanitarian assistance - and to leave the rest to civilian specialists.

"The military should not take on what [the US Agency for International Development] does or the State Department," Bacon said. Still, US military strategists believe they have an expanding role to play in exerting America's soft power.

They began to embrace the concept - a term coined by Harvard professor Joseph Nye - after the South Asian tsunami in late 2004, when the United States mustered a flotilla of ships and dozens of aircraft to ferry aid to hundreds of thousands of people in coastal villages in Indonesia, the world's largest Muslim nation.

"The standing of the United States in Indonesia had dropped very low as a result of the Iraq war but went up impressively after the tsunami relief," said Nye, a former assistant secretary of defense who now teaches at the Harvard Kennedy School.

As a result, the chairman of the Joint Chiefs of Staff is now required to draft military doctrine for how to conduct "stability" operations, including assisting countries in the event of an emergency, and is formulating new curriculum for military training schools to elevate nonmilitary tasks in the minds of the officer and enlisted ranks.

Meanwhile, the Navy's new maritime strategy, issued in late 2007, states that "preventing wars is as important as winning wars."

The generals and admirals who oversee American forces around the world now regularly include humanitarian and stability operations in their annual schedule of war games and day-to-day operations.

One day this month, the commander of the 13th Air Force - the largest air combat unit in the region - was helping coordinate disaster assistance across East Asia.

"More often than not out here in the Pacific we deal with disasters," said Lieutenant General Loyd S. "Chip" Utterback, the 13th Air Force commander.

"If there is not an earthquake a day going on, there is certainly a volcano erupting. There are landslides in the Philippines, floods in Vietnam and Burma. India and Bangladesh deal with flooding, cyclones, typhoons. Those skills that we use to go to battle are easily transferable in many cases."

To expand the soft power tools in its quiver the military is in the process of enlisting more specialists and training a new generation of officers in the concept of "peacetime engagement."

"The time we are concentrating on it is huge," said Colonel Sean Murphy, an Air Force medical doctor who recently organized a weeklong training course for health officials in Southeast Asia.

"We really believe this is pure preventative medicine, no different than taking cholesterol pills to prevent that heart attack." But Bacon and others say there must be a similar expansion at the State Department.

"The whole question of how we organize ourselves to interact with fragile and failing states is a crucial one," Bacon said.