The U.S. and China have a long relationship that often has been characterized by mutual suspicion. One step forward in relations is often followed by one step back.

But behind the scenes, overshadowed by jockeying between the countries' diplomats and statesmen, the U.S. and Chinese militaries have plodded forward, building relationships that Pacific Air Forces leaders hope will create the basis for future cooperation in the region.

"The overall U.S.-China relationship has been improving, and (military-to-military relations) foster mutual understanding and prevent misunderstanding and miscalculation," said Brian Woo, foreign policy adviser to PacAF commander Gen. Howie Chandler. "It moves us toward a multilateral environment that is more constructive."

In 2008, PacAF and U.S. Pacific Command conducted several exchanges of senior leaders and noncommissioned officers, and more are expected in 2009. The Chinese in October suspended military exchanges for the rest of the year because of outrage over U.S. arms sales to Taiwan, but Woo said he expects them to resume next year.

Still, regional experts and PacAF officials disagree about the value of such military-to-military relations. Woo and Chandler maintain they are essential to U.S. strategy in the Pacific, but some analysts argue they yield little of value to the U.S.

To mil-to-mil proponents such as Woo, gradually building relationships between the countries' uniformed services will lead to greater cooperation in areas of common interest such as combating terrorism, providing maritime safety and responding to natural disasters and humanitarian crises. Eventually, those relationships could help defuse an international crisis.

"This is a soft-power approach," Woo said. "It is a form of diplomacy. ... The resources and the impact that the military has around the world ... on the diplomatic front is profound."

But to others, the pomp and circumstance of military exchanges don't disguise a relationship that remains dominated by mistrust. There also is a feeling that the level of sharing has not been equal between the two sides, said John Tkacik, a former American diplomat in China who is senior fellow in Asian studies at the Heritage Foundation, a conservative think tank in Washington.

"The Chinese do not really give Americans that much access to their facilities, certainly not as much as we have been giving to the Chinese," he said. "And I think there was a feeling, especially in the Pacific, that we were probably showing the Chinese too much and we were getting nothing in return."

Even proponents agree that mil-to-mil relations have not always been on equal footing. Kenneth Allen, an analyst for the CNA (formerly the Center for Naval Analyses) noted in testimony last year before the U.S.-China Economic and Security Review Commission and in a 2006 presentation at Fudan University in China that the Chinese typically take Americans to "show bases" from which the Americans can learn little, whereas the Americans give the Chinese access to important installations such as Hickam Air Force Base, Hawai'i.

U.S. forces in the Pacific have hosted Chinese military officials three times in 2008. Chandler and PacAF vice commander Maj. Gen. Mike Hostage hosted Lt. Gen. Zhang Qinsheng, Guang-zhou military region commander for the People's Liberation Army, on July 9 and Lt. Gen. Jiang Jianzeng, Nanjing Military Region Air Force commander for the People's Liberation Army Air Force, July 14-19.

Woo characterized the meetings as "cordial and frank," and said "the atmospherics were very good."

But U.S.-Chinese military exchanges don't involve only officials with stars on their shoulders. U.S. Pacific Command hosted an NCO exchange in Hawai'i on Oct. 1-2, and a delegation of American NCOs visited China in June to discuss enlisted issues.

Chief Master Sgt. Todd Salzman, the 13th Air Force command chief, said the most noticeable difference he saw between the U.S. and Chinese militaries was the role of the NCO corps. Chinese NCOs are often excellent technicians, he said, but aren't given the same degree of responsibility as in the U.S.

No military exchanges are planned thus far for 2009, although a Chandler spokesman said he has been invited to China and looks forward to the trip.

In an e-mail to Air Force Times, Chandler said the general remains bullish on the value of mil-to-mil exchanges with China, but he also sounded a note of realism and caution.

"We need to ensure that we do not miscalculate and ... misunderstand each other," he said. "I think we have an opportunity so long as we deal with the Chinese from a position of strength."