The Vietnamese. in their quest for domination over all of Indochina. have given a new term to our language: "boat people." And in late 1978. Vietnam. with the support of the Soviet Union. invaded Cambodia. driving the infamous and brutal regime of Pol Pot from Phnom Penh and setting up an unrepresentative regime under a former Khmer Rouge military commander named Heng Samrin. a regime which is dependent for its survival on the presence of about 200.000 Vietnamese forces. For several months now some 50.000 to 70.000 Vietnamese troops have been pressing up against the Thai border. bringing additional refugee pressure on Thailand and threatening that countrys stability and security. The challenge posed to stability in Asia by Vietnams actions is a serious one indeed. For the United States. less than five years after the end of our Indochina tragedy. it poses especially painful problems.