Compiling an enemies list was a cinch for the United States during the Cold War, what with most of the Soviet Union’s nuclear arsenal targeted its way. Friends of the Soviets immediately became America’s enemies, and Soviet enemies became U.S. friends. That made China a U.S. enemy of the highest order, a ranking shared by the Soviet client-states of Cuba, North Korea, and North Vietnam, against which the United States fought. Muammar Gaddafi's Libya rose to high-enemy status under President Ronald Reagan, a position it maintained until he surrendered its nuclear program.
The spilling of blood and burning of factories by anti-Chinese rioters sweeping across Vietnam reinforces Beijing’s message to other countries claiming territory in the South China Sea: resistance is costly and ultimately futile.
After America’s ignominious defeat and hurried departure from Vietnam in 1973 -- when the world’s richest and mightiest nation was humbled by the stolid determination of ill-equipped, ideologically inspired peasants -- it was generally assumed the United States would not wage war again until the lessons of the Viet Cong victory were taken to heart.