Despite threats to teach Vietnam "another lesson," China has been withdrawing some ground and air forces from the Vietnamese border in recent weeks and does not appear ready to attack, according to analysts here.

The reduction of Chinese forces comes as the Vietnamese reinforce their frontier forces, depleted by the border war that ended in March, and as both Vietnamese and Chinese diplomats continue to hurl insults at negotiating talks in Hanoi.

[China has made the withdrawal of Vietnamese troops from Cambodia a "precondition" of normalization of relations between Peking and Hanoi, the chief Vietnamese negotiator, Phan Hien, told a press conference after today's negotiations.]

At the third session of the talks today, both the Chinese and Vietnamese sides accused each other of increasing tension and seemed to hold out little hope of any solution to their dispute. Some analysts here predicted that the talks would accomplish nothing but an exchange of prisioners.

Western analysts have estimated that about 250,000 Chinese troops took part in some way in China's February invasion of Vietnam, which came in respond to Vietnamese border harassment and Hanoi's defeat of a Cambodian government that had been allied with Peking. Perhaps 100,000 Chinese troops actually crossed the border. A top Chinese general reportedly told a visiting French delegation recently that 20,000 Chinese troops were killed or wounded in what the Peking called a "counterattack in self-defense."

Analysts here said Chinese troops strength near the border still appeared to be much greater than it was last year, before Peking began to build up its forces for the invasion. "But with them withdrawing both ground and air forces, it doesn't seem like they intend to start anything, at least not for a few weeks," one analyst said.

Chinese Vice Premier Deng Xiao-ping (Teng Hsiao-ping) reportedly told visiting U.N. Secretary General Kurt Waldheim last week that a new "counterattack" might be necessary if Vietnam did not cease continued alleged border provocations. Former U.S. secretary of state Henry Kissinger, visiting Peking about the same time, reportedly heard more ambivalent statements from Chinese officials on the prospects of a new border war.

Chinese Vice Foreign Minister Han Nianlong, speaking at the border talks in Hanoi today, sharply criticized Vietnam for the invasion of Cambodia and what he said was the Vietnamese plan to take over all of Indochina. "Your deed does not square with your word," he said. "Your self-contradictory and perfidious attitude shows that you are out-and-out hypocrites. You have lost your credibility before the whole world."

Han's diatribe contained no threat to begin fighting again, but seemed to give little hope for progress in the negotiations. He asked the Vietnamese to study again an eight-point Chinese proposal, which included provisions such as the repatriation of refugees who have crossed into China. Hanoi has publicly rejected the Chinese proposal.

On the Vietnamese side, Vice Minister Phan Hien, complained today of what he said were "daily armed provocations against Vietnam on the ground, in the air and on the sea." He listed several alleged incidents of Chinese troops firing across the border, laying land mines on Vietnamese soil or moving across the border in large groups.

Phan Hien also proposed, however, that the next session be devoted to discussing border issues and prisoner exchange, according to the Vietnam News Agency. A report from Hanoi said the Vietnamese gave the Chinese a list of 240 Chinese soldiers being held prisoner.

The New China News Agency later said Han asked for a preliminary oral agreement to exchange prisoners under Red Cross supervision but the Vietnamese "denied an answer."

The high Chinese military officer reporting Chinese casualties also told the French visitors that 50,000 Vietnamese had been killed or wounded in the month-long border war. Western analysts are unable to confirm the casualty figures.