Saigon’s fall ten years ago was the Soviet Union’s greatest victory in one of the key battles of the Third World war. No Soviet soldiers fought in Vietnam, but it was a victory for Moscow nonetheless because its ally and client, North Vietnam, won and South Vietnam and the United States lost. After we failed to prevent Communist conquest in Vietnam, it became accepted dogma that we would fail everywhere. For six years after Vietnam, the new isolationists chanted “No more Vietnams” as the dominoes fell one by one: Laos, Cambodia, and Mozambique in 1975; Angola in 1976; Ethiopia in 1977; South Yemen in 1978; Nicaragua in 1979. Since President Reagan took office in 1981, America’s first international losing streak has been halted. But the ghost of Vietnam still haunts the debate over aid to the government of El Salvador and to the anti-Communist contras in Nicaragua. If we fail to halt Soviet support of aggression in our own hemisphere, we will have little hope of doing so when our interests are threatened in other parts of the world.