More than six decades ago, American military pilots flew numerous risky missions over "the Hump" via the Himalaya Mountains to resupply the Flying Tigers and the Chinese Government during World War II. The pilots who navigated this dangerous air route between India and China in the 1940s were a great help to the country, and China considered their missions to be critical lifelines.

Sixty years later, two U.S. military planes touched down again in southwest China where a terrible earthquake struck on May 12. This time, they carried water, food, generators, blankets and other relief supplies for the victims, conjuring up visions of similar kind deeds decades ago.

While the U.S. military's assistance has been a small part of the overall international aid that has poured into China since the disastrous earthquake, the interaction between American and Chinese soldiers and officers may indicate brighter prospects for further coordination, according to Chinese international affairs experts. It also may point to a discernible shift in China's attitude toward foreign assistance and the outside world at large, they said.

The touchdown of U.S. military planes on Chinese territory and China's acceptance of their help represent a certain degree of mutual trust that creates a friendly atmosphere for bilateral military cooperation, said Tao Wenzhao, a research fellow at the Institute of American Studies of the Chinese Academy of Social Sciences.

In addition to the cargo planes loaded with relief supplies, the Pentagon announced it would render another kind of assistance. It said on May 19 that the U.S. National Geospatial-Intelligence Agency would provide China with satellite imagery upon request in an effort to help the Chinese Government determine the extent of the damage from the earthquake and the aftershocks in Sichuan Province.

The friendly gesture on the part of U.S. military certainly creates a friendly atmosphere for future cooperation, said Xiong Zhiyong, a professor specializing in China-U.S. relations at China Foreign Affairs University.

The American military is active in carrying out humanitarian operations to enhance U.S. soft power and project a positive image of the country, Tao said. This has enabled the United States to play a role in strategically important regions and show its sense of responsibility as a great power, he added.

Although military aid for disaster relief in foreign countries is nothing new for the United States, the assistance provided by American armed forces this time still demonstrates their goodwill to maintain a sound relationship with China, Xiong said. One thing particularly noteworthy has been China's frank and open attitude in handling the U.S. assistance, both scholars said.

There were few, if any, precedents, in which China has accepted international aid from foreign militaries, Xiong said. When previously hit by natural disasters, China seldom requested or accepted large-scale international aid. Most of the accepted relief materials and donations came from foreign governments or NGOs.

A hotline between China and the United States also has played a role in the military interaction this time. After the U.S. planes successfully landed and handed relief supplies over to China, Lieutenant General Ma Xiaotian, Deputy Chief of the General Staff of the People's Liberation Army, talked with Admiral Timothy Keating, Commander of the U.S. Pacific Command, via the hotline, which the U.S. Department of Defense and Chinese Ministry of National Defense established late last year.

The setting up of the military hotline had been initiated by Peter Rodman, U.S. Assistant Secretary of Defense, during the eighth round of the Sino-U.S. defense consultations in 2006 and finalized during U.S. Defense Secretary Robert Gates' visit to China in November 2007. The talk between Gates and Liang Guanglie, China's Minister of Defense, via the military hotline earlier this year marked its first use.

In the most recent phone conversation, Ma conveyed his gratitude for the U.S. assistance. The officials also shared their thoughts on the disaster response and other assistance needed by China.

The use of the military hotline opens up new prospects for mutual exchanges of views and facilitates communication, Tao said. Serving as a military-to-military communication channel, the hotline is conducive to improving mutual understanding, he added.

Echoing Tao's remark, Xiong said he considers the military hotline to be important in facilitating relevant exchanges between the two sides. It makes communications easier and reflects the will of both sides to talk with each other in a frank and straightforward manner. But Xiong also believes that the military hotline may be more significant when real tensions build and crises arise between the two nations.

Assistance for quake relief is not such a controversial issue compared with other complex military problems facing the two countries, including national security, strategic interests, ideology and other intricate factors, Xiong said. By the same token, their willingness to talk does not promise a bed of roses in the development of their bilateral relations, he said, although the U.S. assistance to China is a good sign for future development.