China's bulwark against Asia's new imperialists

American diplomats are gambling that China, the most aggressive and successful imperialist power in Asian history, will be willing and able to preserve peace -- or relative peace -- in the threatened Asia of today.

They are depending primarily upon the Chinese to halt a deeper Vietnamese thrust into vulnerable Southeast Asia.

The United States defeat in Vietnam ended the 30-year American effort to preserve peace in East and Southeast Asia -- by fighting for it if necessary. Asian leaders are just beginning to realize the enormity of this defeat. All of them now appear to recognize, at least privately, that there is little or no chance another American expeditionary force will land again anywhere in Asia, except possibly in South Korea.

This means that Southeast Asia is without foreign Caucasian defenders for the first time in more than two centuries. For all their real and presumed faults as colonial overlords, the West Europeans kept a historically quarrelsome region in relative peace and safety from outside attack, sometimes at considerable sacrifice. When foreign control ended, all of the enmities and ambitions and suspicions of the centuries exploded, and Asia has been at war continually since 1945.

Nevertheless, the Asians still are too fragmented by their ancient and modern hostilities and fears to form any meaningful defense coalition, such as NATO. Instead, the American pullout from Vietnam in 1975 sent Southeast Asian leaders scurrying for a new defender. All turned with a certain trepidation to China. The Imperial Chinese once controlled or received tribute from every country in modern Southeast Asia. The communist Chinese once published a map claiming sovereignty over all these nations -- and have never repudiated the claim.

Today, the Chinese pose the only military barrier of consequence against Asia's newest imperialistic power -- Vietnam. Despite all their "revolutionary" propaganda, the Vietnamese conquered Laos and Cambodia like 18th-century imperialists and with no more valid justification. With a military establishment which is believed to be stronger than the combined arms of their neighbors, the Vietnamese are poised on the borders of Thailand with menacing power. They have invaded Thai territory with frequent impunity in claimed hot pursuit of troops of the deposed Pol Pot communist Cambodian regime.

Diplomats in the region say only China poses any threat of counterforce against a Vietnamese drive deeper into Southeast Asia. But this deterrent has been weakened by recent events and may prove to be invalid in a major showdown.

Competent sources in Peking say the Chinese failed dismally in their first attempt to control Vietnamese expansion -- the 1979 invasion of North Vietnam. The operation apparently was designed to force the Vietnamese to withdraw from Cambodia and to abandon their attempt to destroy the Chinese- backed Pol Pot regime. Neither has happened.

Instead, the Vietnamese fought off the Chinese hit-and-run invasion and immediately began to build new defenses against any second Chinese thrust. The informants say Hanoi now maintains 60 percent of its regular army on the sensitive Chinese frontier. The Chinese campaign, they add, was too hastily planned and executed to accomplish its purpose. Numerous military liabilities appeared, including inadequate communications and performance failures by Chinese tanks.

The invasion also created the probability that another Chinese peacekeeping operation would spark Soviet retaliation, the sources added. Moscow did nothing in 1979 but might be obliged to respond to a second Chinese attack on Vietnam, if only to maintain face. China is still menaced by the massed Soviet army of 43 divisions, strung along a 2,300-mile border.

The Chinese say their primary concern is to prevent further encirclement by the Soviets and their current allies, the Vietnamese. But Peking has given no indication of abandoning its own ambitions. China was Asia's most active post- 1945 imperialist, until Vietnam took over the title. The Chinese conquered Tibet in 1949, invaded India in 1962 and Burma in the 1970s, and fought a continuous military-political war against Taiwan for more than 20 years.Peking's claims to Tibet and Taiwan are based upon disputable grounds, which many diplomats say are untenable.

The United States is giving limited and careful support to China with clear recognition of the risks. But Asia has no other regional defender today.