Dominoes

"No one can say with absolute certainty what would have happened had South Vietnam been defeated in 1965, considering the complex interaction of many individuals with a diverse array of personalities, cultures, and limitations, and considering the powerful role of chance in human conflict. What can be said, based on analysis of the information available then and subsequent revelations, is that staying in South Vietnam in 1965 was a much more promising option for the United States than leaving, even if it meant fighting the war in the flawed way that the United States ultimately fought it. High was the probability that the fall of Vietnam in 1965 would have knocked over many dominoes in Southeast Asia."

Mark Moyar, Triumph Forsaken: The Vietnam War, 1954-1965 (New York: Cambridge 2006), at 388.