QUITE A COUNTRY, Vietnam: twice within a year its behavior has drawn upon it wellfounded charges of genocide. The first time, charges arose from Hanoi's policy of forcing tens of thousands of its longtime citizens of Chinese ancestry onto the high seas in boats no better than floating coffins. Uncounted thousands died before an international outcry ended at least the most egregious manifestations of that policy.

Having practiced genocide on one ethnic group, Vietnam promptly turned upon another. As part of an evident effort to dominate the whole Indochinese peninsula, Hanoi has put hundreds of thousands of Cambodians -- perhaps even millions -- under the threat of starvation. These people have been driven from their homes and fields into barren no-man's-lands where all the combatants in the continuing war in Cambodia, but especially the Vietnamese, are using crop destruction and denial tactics to impose their political control.

The international relief agencies have been beseeching Hanoi, which manipulates a puppet regime in Phnom Penh, to let them in to do what they can in a country so devastated anyway by years of violence that, in the best of circumstances, relief would be a spotty thing. But while Hanoi has made gestures of cooperation, it has effectively prevented the agencies from doing more than token service. It seems to be part of Hanoi's plan to use what it calls the "food shortage" to solve what is in its expansionist view a real problem in Cambodia: the presence of Cambodians, Genocide, far from being an incidental product of a political decision; almost seems to be the decision. Vietnam does not appear to want Cambodians to be saved from famine even in the parts of Cambodia that it controls.

Some thousands of hapless Cambodians are now crossing over to adjacent sections of Thailand. The United States is assisting in the international effort to care for that relatively small part of the population for which the Thai option is available. But for the great majority, things are different: extreme malnourishment and rampant malaria are taking a terrible toll. The effect on the general health and the birth rate has been such as to raise the possibility that a next generation of Cambodians will not be born or, if one is, that it will not survive in any numbers or strength.

The Vietnamese may not care about the Cambodians. Do they care about themselves? They are cutting themselves off for years to come from association with people and nations that care about human life. They will end up with no foreigners to turn to except the Russians. They invite and deserve contempt.