YET ANOTHER vast - and predictable - human tragedy is brewing in Southeast Asia, and, as in the case of the boat people, it appears that the international community may wait until thousands are dying before taking action to alleviate the suffering. Reports from Cambodia are that the people of that devastated country, who have endured the ravages of the Pol Pot regime and the Vietnamese invasion, may soon face another scourge: famine.

According to the few outsiders who have visited the country in the last few months, Cambodia's agricultural system, already shaky, was reduced to a shambles by the Vietnamese invasion last spring and the ensuing conflict between Vietnamese and Chinese-backed factions. Seed stocks were destroyed, and planting and cultivating interrupted by the fighting. One report says that no more than 5 percent of the fields are under cultivation, and that those that are will yield little because near-starving peasants have eaten the rice seedlings. In short, it is possible that there will be little or no harvest in Cambodia this year. The consequences - in a country whose doctors and hospitals both have been systematically wiped out - could be starvation or death for literally millions. Alternatively, Cambodians may start to head for Thailand en masse: creating an enormous new refugee population and seriously threatening the stability of the already overburdened Thai government.

State Department officials foresaw the coming crisis last spring and have been prodding various international organizations, but with only limited success. Many of those involved doubted the predictions that were being made and wanted more solid information before taking action. Some of the United Nations' agencies are barred from helping because the U.N. recognizes the ousted Pol Pot government and not the Vietnamese-installed government of Heng Samrin. Other agencies, such as the International Red Cross and UNICEF, have been unable to reach an agreement with the REACH AN AGREEMENT with the Cambodian government that would assure that the food they provide goes to the general population and not to the troops of either faction. This country's ability to provide assistance is hampered - though not foreclosed - by conflicting legislation prohibiting aid to Cambodia. But the major obstacle to averting starvation continues to be indifference in both Hanoi and Peking. Both of those governments remain committed to settling their political struggle, and so far have been unwilling to let the prospect of even massive human suffering upset their plans.

What is needed now is a strong effort to train international attention on this problem before it reaches the proportions of a major calamity. Neither Hanoi nor Peking is likely to be totally impervious to the united force of world opinion. All that is really needed is an agreement to allow an international presence, such as that of the Red Cross, to ascertain the dimensions of the problem and then supervise the distribution of vitally needed food.There has been a surfeit of suffering in Southeast Asia already. This time a remedy is at hand, if only there is the will to use it.