By Richard Baum, Ph.D., University of California, Los Angeles
By the first half of 1968, Sino-Soviet relations had basically reached a boiling point, with the two sides routinely excoriating each other in the harshest and strongest possible language. The straw that broke the camel’s back was the Soviet decision to send tanks and troops into Prague, Czechoslovakia, in August 1968. How did China react?

Sparring over Czechoslovakia and the Brezhnev Doctrine
In Prague, a liberal, reform-minded Communist leader, Alexander Dubcek, had recently become the head of the Czech Communist Party. With Dubcek promising to dismantle the country’s neo-Stalinist institutions and pursue a path of social democracy, Moscow intervened in force, removing Dubcek and restoring to power a more orthodox regime. Although China had no love either for the liberal Dubcek or his reformist government, they bitterly protested the unilateral Soviet military action.

China’s leaders were particularly upset over the Soviet rationale for this invasion, which was formulated by Leonid Brezhnev himself, and which soon became known as the “Brezhnev Doctrine”. The core of the “Brezhnev Doctrine” was the idea that members of the Socialist bloc enjoyed only limited and conditional sovereignty—at the pleasure of the USSR. In Mao’s view, this was a convenient rationale that could be invoked by Soviet leaders to legitimize the unilateral use of force against any member of the Communist bloc at any time, and under any circumstances, Moscow viewed as a threat to its national interests.
In short, it was a one-size-fits-all excuse for Soviet-armed intervention. Today Prague; tomorrow—Beijing? Although Mao has often been called paranoid, in this case, his fears were not entirely unwarranted. The Soviet Union was gearing up for war.
Since the late 1950s, Moscow had watched Mao’s growing radicalization with alarm. Repeatedly, Kremlin leaders had accused Mao of leading China— and the Socialist Camp—on the road to ruination. In response, the Soviets had amassed more than a dozen combat-ready divisions along the Chinese border—many of them equipped with tactical nuclear weapons.
Learn more about Mao’s deepening differences with Moscow as Khrushchev rejected Stalinism.
Sino-Soviet Border Conflict
All along the 4,000-mile Sino-Soviet border, there were increasingly tense confrontations. Most often, the encounters were marked by shouting back and forth; other times, fistfights actually broke out; and occasionally, isolated shots were fired.
Armed conflict finally broke out in early March of 1969, when a Chinese border patrol ambushed a Soviet patrol on a small island in the middle of the frozen Ussuri River in Northeast Manchuria. The Soviets suffered 31 dead and 14 wounded in the initial skirmish.
Two weeks later, on March 15, a much larger battle ensued, in the course of which a devastating Russian artillery barrage against Chinese troops concentrated on the southern side of the river inflicted over 800 Chinese casualties. Reportedly, the Russians suffered just 60 dead and wounded in this second round of battle.
This is a transcript from the video series The Fall and Rise of China. Watch it now, on Wondrium.
Reasons for Mao’s Provocation
Why would Mao deliberately provoke the Russians if he wished to avoid a war with them? There are a number of conceivable explanations, some more plausible than others. The most likely (though by no means firmly proven) of these holds that Mao, in his desire to portray the Russians as conquest-minded aggressors, tried to frame them for initiating the March 2 incident in the hope of convincing the United States of Brezhnev’s warlike intentions.
Indeed, this might well have succeeded, except for the fact that high-altitude American U-2 reconnaissance aircraft had photographed the battlefield. And the photos clearly showed that the Soviet patrol had been caught out in the open, where they were totally exposed to enemy fire, a fact that strongly suggests a deliberate Chinese ambush.
An Interesting Hypothetical Question
In August of 1969, a Soviet embassy staff member in Washington, DC, approached his American counterpart at a local coffee shop with a hypothetical “what if” proposition: “What would the United States do” he asked, “if we [the Soviet Union] neutralized the Chinese nuclear weapons complex at Lop Nor in Xinjiang?” He hastened to add that this was merely a hypothetical question.
According to an authoritative account of this incident, the Russians hoped that the Americans would simply look the other way in the event of such an attack, maintaining an attitude of benign neutrality while the Russians proceeded to pound the Chinese nuclear weapons into destruction. The Cold War had now reached a critical crossroad. The response of the US Government was absolutely critical.
A new Republican administration had recently come to power in Washington, headed by President Richard Nixon. This was the biggest, most strategically consequential decision he could possibly be called upon to make—whether to tacitly conspire with the Soviets to neutralize China’s war-making capacity or, alternatively, to somehow try to turn the intense hostility between Russia and China to America’s own strategic advantage.
Learn more about the momentous shift in Sino-American relations under the Nixon presidency.
One Hypothetical Future Destroyed
Had Nixon given the Soviets any encouragement at all in August of 1969, the history of the next 40 years might have been written very differently. But they did not. Nixon categorically rejected the “hypothetical” Soviet proposal.
In so doing, they pointed out to the Russians that any attack on the Chinese heartland, no matter how precisely targeted and well-intentioned, would have a strong destabilizing effect on the balance of power in Northeast Asia and would be utterly unacceptable to the United States.
Common Questions about the Relations between the USSR and China Post 1965
The Brezhnev doctrine suggested that if a socialist country moved toward capitalism, it would become a problem for all other socialist countries. The doctrine made Sino-Soviet relations suffer due to its ramifications.
Russia took military action when the leader of Czechoslovakia espoused liberal views and replaced him with a hardliner. Even though it worsened Sino-Soviet relations, the actions were justified by Brezhnev as his doctrine.
One reason could have been that Mao planned to frame Russia for the conflict, making America believe that Russia has warmongering tendencies, a blow to Sino-Soviet relations.