It would seem natural for the 20th century's two great communist powers, the Soviet Union (U.S.S.R.) and the People's Republic of China (P.R.C.), to be staunch allies. However, for much of the century, the two countries were bitterly and publicly at odds in what is called the Sino-Soviet Split. But what happened?
Essentially, the split actually began when Russia's working class under Marxism rebelled, while the Chinese people of the 1930s did not - creating a divide in the fundamental ideology of these two great nations that would eventually lead to the split.
Roots of the Split
The basis of the Sino-Soviet Split actually goes back to the writings of Karl Marx, who first put forth the theory of communism known as Marxism. Under Marxist doctrine, the revolution against capitalism would come from the proletariat - that is, urban factory workers. At the time of the 1917 Russian Revolution, middle-class leftist activists were able to rally some members of the small urban proletariat to their cause, in accordance with this theory. As a result, throughout the 1930s and 1940s, Soviet advisers urged the Chinese to follow the same path.
China, however, did not yet have an urban factory worker class. Mao Zedong had to reject this advice and base his revolution on rural peasants instead. When other Asian nations such as North Korea, Vietnam, and Cambodia began to turn to communism, they also lacked an urban proletariat, so followed a Maoist path rather than the classical Marxist-Leninist doctrine - to the Soviets' chagrin.
In 1953, Soviet Premier Joseph Stalin died, and Nikita Khrushchev came to power in the U.S.S.R. Mao considered himself now the head of international communism because he was the most senior communist leader. Khrushchev did not see it that way, since he headed one of the world's two superpowers. When Khrushchev denounced Stalin's excesses in 1956 and began "de-Stalinization," as well as the pursuit of "peaceful coexistence" with the capitalist world, the fissure between the two countries widened.
In 1958, Mao announced that China would take a Great Leap Forward, which was a classic Marxist-Leninist approach to development at odds with Khrushchev's reformist tendencies. Mao included the pursuit of nuclear weapons in this plan and disparaged Khrushchev for his nuclear detente with the United States - he wanted the P.R.C. to take the place of the U.S.S.R. as the communist superpower.
The Soviets refused to help China develop nukes. Khrushchev considered Mao a rash and potentially destabilizing force, but officially they remained allies. Khrushchev's diplomatic approaches to the U.S. also led Mao to believe that the Soviets were a potentially unreliable partner, at best.
Cracks in the Sino-Soviet alliance began to show publicly in 1959. The U.S.S.R. offered moral support to the Tibetan people during their 1959 Uprising against the Chinese. The split hit the international news in 1960 at the Romanian Communist Party Congress meeting, where Mao and Khrushchev openly hurled insults at one another in front of the assembled delegates.
With the gloves off, Mao accused Khrushchev of capitulating to the Americans during the 1962 Cuban Missile Crisis, and the Soviet leader replied that Mao's policies would lead to nuclear war. The Soviets then backed India in the Sino-Indian War of 1962.
Relations between the two communist powers had completely collapsed. This turned the Cold War into a three-way standoff among the Soviets, Americans, and Chinese, with neither of the two former allies offering to aid the other in taking down the rising superpower of the United States.
As a result of the Sino-Soviet Split, international politics shifted during the latter half of the 20th century. The two communist powers nearly went to war in 1968 over a border dispute in Xinjiang, the Uighur homeland in western China. The Soviet Union even considered carrying out a preemptive strike against the Lop Nur Basin, also in Xinjiang, where the Chinese were preparing to test their first nuclear weapons.
Oddly enough, it was the U.S. government that persuaded the Soviets not to destroy China's nuclear test sites for fear of sparking a world war. However, this would not be the end of the Russian-Chinese conflict in the region.
When the Soviets invaded Afghanistan in 1979 to prop up their client government there, the Chinese saw this as an aggressive move to surround China with Soviet satellite states. As a result, the Chinese allied themselves with the U.S. and Pakistan to support the mujahideen, Afghan guerrilla fighters who successfully opposed the Soviet invasion.
The alignment flipped the following year, even as the Afghan War was ongoing. When Saddam Hussein invaded Iran, sparking the Iran-Iraq War of 1980 to 1988, it was the U.S., the Soviets, and the French who backed him. China, North Korea, and Libya aided the Iranians. In every case, though, the Chinese and the U.S.S.R. came down on opposite sides.
The Late 80s and Modern Relations
When Mikhail Gorbachev became the Soviet premier in 1985, he sought to regularize relations with China. Gorbachev recalled some of the border guards from the Soviet and Chinese border and reopened trade relations. Beijing was skeptical of Gorbachev's policies of perestroika and glasnost, believing that economic reforms should take place before political reforms.
Nonetheless, the Chinese government welcomed an official state visit from Gorbachev late in May of 1989 and the resumption of diplomatic relations with the Soviet Union. The world press gathered in Beijing to record the moment.
However, they got more than they bargained for - the Tiananmen Square Protests broke out at the same time, so reporters and photographers from around the world witnessed and recorded the Tiananmen Square Massacre. As a result, Chinese officials were likely too distracted by internal issues to feel smug about the failure of Gorbachev's attempts to save Soviet socialism. In 1991, the Soviet Union collapsed, leaving China and its hybrid system as the world's most powerful communist state.