after the Zhenbao Island Incident in 1969, when the Soviet Union reportedly considered the possibility of launching a large-scale nuclear strike against China, and the Chinese leadership, including Mao, was evacuated from Beijing, before both sides eventually returned to diplomatic negotiations.

In the Western world, the Sino-Soviet split transformed the bi-polar cold war into a tri-polar cold war. The rivalry facilitated Mao's realization of Sino-American