America's senior military officer, Gen. Peter Pace of the Marine Corps, has just completed a visit to China during which he nudged along gradually expanding contacts between Chinese and U.S. military leaders that included seeing weapons and command posts that before had been off limits to Americans.

At the same time, the general, who is chairman of the Joint Chiefs of Staff, cautioned the Chinese in public not to miscalculate American capabilities or intentions. Other U.S. officers have done the same, but in private. Pace proposed that the U.S. and China set up a "hot line" between Beijing and Washington to head off potential confrontations.

In an interview in Hawai'i on his way back to Washington, Pace said the Chinese "treated me better, I think, than they've treated any other U.S. officer." He said "there were five or six things they had me do that no one else did," including climbing into a Russian-designed SU-27 fighter plane and riding in a T-99 tank.

Pace was invited into a Chinese general's office where China's war maps were displayed, and then went into a command post with more displays and a table showing the disposition of Chinese forces. "They were very open about that," Pace said.

Over the past decade, the U.S. and China have slowly increased military exchanges, mostly by the U.S. admirals who have led the Pacific Command from its headquarters in Hawai'i. Those exchanges were interrupted in 2001 when a Chinese fighter plane collided with a U.S. EP-3 reconnaissance plane over the South China Sea. They resumed after that episode was resolved.

Even so, American leaders have long complained that China's Peoples Liberation Army lacked transparency, meaning the PLA sought to keep secret budgets, arms development and procurement, and strategy and doctrine.

Secretary of Defense Robert Gates told reporters in Washington recently that China's 18 percent increase in defense spending, its anti-satellite missile shot in January, and its aggressive submarine operations over the last year added up to "a significant investment in their military forces."

Gates continued: "I think that greater transparency would help from the standpoint of the Chinese in terms of both what they are doing and what their strategies are, their intent in modernizing their forces." He urged the Chinese to show "a greater openness about their purposes."

In China, Pace said his comment about miscalculation was not intended as a warning. "It was really a concern that I just wanted to voice publicly for everybody," he said. The general said he wanted to engage not only senior Chinese officers but also junior officers and enlisted people so that "you can build the understanding that will avoid miscalculation."

Pace said he thought his message had gotten through. In a wrapup discussion with a Chinese general, Pace said he heard some of his own words repeated back to him and was told why the Chinese "were anxious to have cooperation."

"I think they took them (his remarks) in the way they were offered, which was a concern that we as military guys have a special responsibility to have as much understanding as possible to prevent miscalculation," he said.

On the hot line, the general suggested it would be a Telex or e-mail connection modeled on the hot line between the Soviet Union and the U.S. during the Cold War. Messages in Russian and English flowed 24 hours a day to keep the line open.

Pace added, however, that "it would also be good to be able to just pick up the phone" to talk with Chinese officers. "Now that I've been there," he said, "it's not a cold phone call, it's a face and a name and a voice that you recognize."

That recalled the lament of Adm. Joseph Prueher, who led the Pacific Command in 1996 when China lobbed missiles toward Taiwan, the island that Beijing claims but which the U.S. is all but committed to help defend. Most Sino-U.S. military exchanges had ceased after the PLA massacred students pleading for democracy in Tiananmen Square in 1989.

Prueher said publicly that he lacked the names of China's military leaders and did not have a telephone number so that he could call to determine what they were up to, and to warn them not to misjudge the potential for an American response.

Instead, amid rising tensions, the admiral deployed two aircraft-carrier task forces to the sea east of Taiwan to warn the Chinese to back off.

Richard Halloran is a Honolulu-based journalist and former New York Times correspondent in Asia. His column appears weekly in Sunday's Focus section.