Without the Vietnam War (say, Nationalists retain Southern China and the Communists Manchuria), what similar foreign fiasco can produce similar effects in the United States? Like effects for example, the New Deal coalition threatened, the counterculture, the disaster that was the 1968 DNC, the collapse of the Cold War consensus, the rise of the New Left, etc., Nixon 1968, etc.?
Indonesia comes to mind, as it nearly fell to communism in the September 30, 1965 Movement.
Besides Indonesia, what countries can become an albatross on US politics, culture and economic affairs?