This particular era of history has always interested me, and it’s a bit complicated, so I made this timeline to help everyone through it. :)
The Sino–Soviet split was the gradual worsening of relations between the People’s Republic of China (PRC) and the Union of Soviet Socialist Republics (USSR) during the Cold War (1945–91). Since 1956, the countries had (secretly) been diverging ideologically, and, beginning in 1961, the Chinese Communists formally denounced “The Revisionist Traitor Group of Soviet Leadership.” In the 1960s, this intellectual divergence became critical, continuing until the late 1980s — yet was rendered moot with the USSR’s disestablishment in 1991. Their doctrinal divergence owed as much to Chinese and Russian national, as with the regimes’ interpretative Marxist ideologies.
- 1939-1945: Second Sino-Japanese War
Mao Zedong fought a war of resistance against the Empire of Japan, while fighting the Nationalists led by Chiang Kai-Shek at the same time. He ignored most of the political and military advice that Stalin gave him because applying (traditional) Leninist revolutionary theory proved difficult. China, unlike Russia, had no great urban working class, thus he organized the peasants and farmers to fight the Chinese Revolution.
- 1939-1945: WWII
Stalin urged Mao to form a coalition with Chiang against Imperial Japan. After the war, Stalin told Mao not to cease power, but to negotiate with Chiang because Stalin had signed a Treaty of Friendship and Alliance with the Nationalists in 1945.
Chiang insisted Stalin act on the USSR’s illegal occupation of Tannu Uriankhai in Northern Mongolia. Stalin broke the treaty requiring Soviet withdrawal from Manchuria three months after Japan’s surrender and gave Manchuria to Mao. Stalin also gave Mao’s party $1 bil in material aid to help expel the Nationalists from continental China and establish the PRC.
- 1947: Stalin denounced Yugoslavia, led by Tito.
- October 1, 1949: Communist China is born under the leadership of Mao Zedong.
- 1950: Sino-Soviet Treaty of Friendship and Alliance
Mao visits Moscow and get $300 mil low-interest loan and a 30 year military alliance.
Simultaneously, Beijing had begun trying to supplant Moscow as the ideological leader of the world Communist movement. Mao (and supporters) had promoted the idea that Asian and world communist movements should emulate China’s model of peasant revolution, not Russia’s model of urban revolution. US journalist Anna Louise Strong had written the article “The Thought of Mao Tse-Tung” and the book Dawn Out of China, reporting that his intellectual accomplishment was “to change Marxism from a European to an Asiatic form . . . in ways of which neither Marx nor Lenin could dream” — which the Soviet government banned in the USSR.
At the first international Communist conclave in Beijing, Mao advocate Liu Shaoqi praised the “Mao Tse-tung road” as the correct road to communist revolution, warning it was incorrect to follow any other road; moreover, he praised neither Stalin nor the Soviet communist model, as had been the practice among Communists. Yet, with politico-military tensions at crisis in the Korean Peninsula, and fear of US military intervention there, geopolitical circumstances disallowed the USSR and the PRC any ideological split, hence their alliance endured.
- 1950-1953: Korean War
- 1953: Stalin dies and Khrushchev comes to power.
temporary revival of Sino-Soviet friendship
- 1954: Khrushchev visits China and hands over Port Arthur naval base to PRC.
Soviets provide technical aid in 156 industries in China’s first 5 year plan and 520 mil rubles in loans.
Geneva Conference of 1954: PRC and the USSR mutually persuaded the Democratic Republic of Vietnam, led by Ho Chi Minh, to temporarily accept the West’s division of Vietnam at the 17th parallel north.
- 1956: Khrushchev denounced Stalin with The Personality Cult and its Consequences.
- 1958-1961: China’s Great Leap Forward
During the 1950s, Soviet-guided China followed the Soviet model of centralized economic development, emphasizing heavy industry, and delegating consumer goods to secondary priority; however, by the late 1950s, Mao had developed different ideas for how China could directly advance to the communist stage of Socialism (per the Marxist denotation), through the mobilization of China’s workers.
Khrushchev’s post-Stalin policies began to irritate Mao, especially that of De-Stalinization and hen he restored relations with Yugoslavia, led by Tito, whom Stalin had denounced in 1947. These occurrences shocked Mao, who had supported Stalin ideologically and politically, because Khrushchev was dismantling Mao’s support of the USSR with public rejections of most of Stalin’s leadership and actions — such as announcing the end of the Cominform, and (most troubling to Mao), de-emphasizing the core Marxist-Leninist thesis of inevitable war between capitalism and socialism.
Khrushchev was advocating the idea of “Peaceful Coexistence”, between communist and capitalist nations — which directly challenged Mao’s “lean-to-one-side” foreign policy, adopted after the Chinese Civil War, when he feared direct Imperial Japanese or US military intervention, the circumstances that pragmatically required a Sino–Soviet alliance. In de-Stalinizing the USSR, Khrushchev was dissolving the condition that had made the Sino-Soviet Treaty of Friendship (1950) attractive to China. Mao thought that the Soviets were retreating ideologically and militarily — from Marxism-Leninism and the global struggle to achieve global communism, and by apparently no longer guaranteeing support to China in a Sino–American war; therefore, the roots of the Sino–Soviet ideological split were established by 1959.
- 1959: Khrushchev meets Eisenhower to decrease Russo-American tensions.
At first, the Sino–Soviet split manifest itself indirectly; polemics between the CPSU and the CPC criticized each others’ pupils — China denounced Tito, Russia denounced Enver Hoxha, leader of the People’s Socialist Republic of Albania
- 1960: Romanian Communist Party Congress
They directly criticized each other in the Romanian Communist Party congress, when Khrushchev and Peng Zhen openly quarreled. Premier Khrushchev insulted Chairman Mao Zedong as “a nationalist, an adventurist, and a deviationist”. In turn, Mao insulted Khrushchev as a Marxist revisionist, criticizing him as “patriarchal, arbitrary and tyrannical”. In follow-up, Khrushchev denounced China with an eighty-page letter to the conference.
Khrushchev also withdrew nearly all Soviet technical experts from China, leaving some major projects in an unfinished state. Many blueprints and specifications were also withdrawn.
November 1960, at a congress of 81 Communist parties in Moscow, the Chinese quarreled with the Russians and with most other Communist party delegations — yet compromised to avoid a formal ideological splitting; nonetheless, in October 1961, at the 22nd Congress of the Communist Party of the Soviet Union they again quarreled openly. In December, the USSR severed diplomatic relations with the People’s Socialist Republic of Albania, graduating the Russo–Chinese ideological dispute from between political parties to between nation-states.
- 1962: Sino Indian War
USSR does not support China. Maintains moderate relation with India, greatly offending Mao Zedong.
The PRC and the USSR broke relations because of their international actions. Mao criticized Khrushchev for withdrawing from fighting the US in the Cuban Missile Crisis (1962). “Khrushchev has moved from adventurism to capitulationism”; Khrushchev replied that Mao’s confrontational policies would provoke a nuclear war.
USSR is alarmed by the Great Leap Forward. USSR has refused to aid Chinese nuclear weapons development and refused to side with them in the Sino Indian War. Mao was offended by all these actions. He perceived Khrushchev as too-conciliatory with the West, despite Soviet prudence in international politics that threatened nuclear warfare (i.e. the US and USSR were nuclear powers by the late 1950s), wherein the USSR managed superpower confrontations such as the status of post-war Berlin.
- June 1963: the PRC published The Chinese Communist Party’s Proposal Concerning the General Line of the International Communist Movement , and the USSR replied with an Open Letter of the Communist Party of the Soviet Union;  these were the final, formal communications between the two Communist parties.
- 1964: China has atomic bomb. Mao said that a counter-revolution in the USSR had re-established capitalism; consequently, the Chinese and Russian Communist parties broke relations, and the Warsaw Pact Communist parties followed Soviet suit.
- 1966-1976: Mao’s Cultural Revolution
Meant to re-establish Mao’s sole leadership of China. Aggravated, then severed PRC-USSR relations and relations with most of the Western world. Still, communist pragmatism: USSR and PRC gave aid to the Vietnamese communists led by Ho Chi Minh. The Chinese permitted Soviet aid materials to travel through China to North Vietnam during the Vietnam War (1945-1975).
- 1967: Red Guards besiege Soviet embassy in Beijing.
Despite unbroken formal diplomatic ties, relations froze in place. The PRC then raised the matter of the Sino–Soviet territorial frontier – Although demanding no territory, the Chinese insisted upon Soviet acknowledgement of that historic Russian injustice against China committed with the Treaty of Aigun (1858) and the Convention of Peking (1860); the Soviets ignored the matter.
- 1968: Border Tensions
The Soviet Army had amassed along the 4,380 km (2,738 mi.) frontier with China — especially at the Xinjiang border, in north-west China, where Turkic separatists might easily be induced to insurrection. Earlier, in 1961, the USSR had some 12 half-strength divisions and 200 aircraft at that border, seven years later, at the end of 1968, they had 25 divisions, 1,200 aircraft, and 120 medium-range missiles deployed there.
- 1969: Political border tensions turn into armed raids and small scale warfare.
Observers predicted inter-communist war. Soviet sources implied a possible first strike against China and military documents indicate that the USSR has more nuclear attack plans against China than against the US. China built large scale underground shelters.
They did not resort to full-scale war. In October, the PRC and USSR began border-demarcation talks, restoring minimal diplomatic communication.
- 1970: Mao understood that the PRC could not simultaneously confront the USSR and the USA, and suppress internal disorder. During that year, when the Vietnam War was at its worst, and Chinese anti-American rhetoric at its zenith, Mao perceived that China’s geographic neighbors, the Soviets, were the greater threat, and thus Mao sought a pragmatic rapprochement with the US, in confronting the USSR.
- 1971: Henry Kissinger visits China.
- 1972: Nixon visits China.
In the 1970s, Sino-Soviet rivalry extended to Africa and the Middle East, where each Communist power funded and supported political parties, armed movements, and states, vis-à-vis the Ogaden War (1977–78) between Ethiopia and Somalia, the Rhodesian Bush War (1964–79), the Zimbabwean Gukurahundi (1980–87), the Angolan Civil War (1975–2002), the Mozambican Civil War (1977–92), and Palestinian factions.
- 1971: Radical phase of Cultural Revolution comes to an end.
PRC gradually begins to return to Communist political normality. The re-establishment of Chinese domestic tranquility ended direct armed conflict with the USSR but did not improve diplomatic relations.
- 1973: Soviet garrisons on the border are double the size of 1969 garrisons. China continued denouncing “Soviet social imperialism” and accusing the USSR of being enemy to world revolution.
- September 1976: Mao dies.
- 1975: Vietnam War ends, Communist victory.
This left Pro-Soviet regimes in Vietnam and Laos, and a pro-Chinese regime in Cambodia.
- 1978: Pol Pot Khmer Rouge Regime in Democratic Kampuchia [Cambodia]
At first the Vietnamese ignored the Khmer Rouge’s murderous domestic policies in Cambodia, but, when their societal reorganization attacked the ethnic Vietnamese in Cambodia, Vietnam deposed Pol Pot in 1978.
- 1975-1979: Cambodian-Vietnamese War – Pol Pot deposed.
PRC denounced the deposition of their Maoist client.
- 1979: Sino-Vietnamese War
PRC invaded northern Vietnam. USSR denounced the PRC’s action.
- December 1979: USSR invades Afghanistan.
The PRC viewed that Soviet action in aid of an ally, as a feint, part of a greater geopolitical encirclement, and so entered a tri-partite alliance with Pakistan and the US to sponsor armed Islamist resistance in Afghanistan to end the Soviet war in Afghanistan (1979–89).
Deng Xiaoping said three obstacles must be removed so that Sino-Soviet relations might improve:
- The amassed Soviet Army at the PRC-USSR border and in Mongolia
- Soviet support of the Vietnamese occupation of Cambodia
- Soviet occupation of Afghanistan
- 1981-1982: Deng Xiaoping distanced the PRC from the US because of its weapons sales to the Nationalist Republic of China in Taiwan island.
- 1982: 12th Chinese Communist Party Congress declared PRC would pursue an independent foreign policy. In Tashkent, USSR (Brezhnev) gave a speech conciliatory towards the PRC. Sino-Soviet relations resumed at the vice-ministerial level.
- 1985: Gorbachev is president of USSR.
He tried to restore relations with the PRC, by:
- reducing the Soviet Army concentrations at the USSR–PRC border and Mongolia
- resuming trade
- dropping the border-demarcation matter.
The matter if the Soviet withdrawal from Afghanistan remained unresolved and relations remained cool.
In May 1989, President Gorbachev visited the People’s Republic of China, whose government were ambivalent about perestroika and glasnost, his reform programs, which ultimately ended communist government and provoked the dissolution of the Soviet Union in 1991. Since the PRC did not officially recognize the USSR as a socialist state, it had no official opinion about how he might reform Soviet socialism; yet privately, the Chinese leaders said it was too early for President Gorbachev’s political reform without his first economically reforming the country — whereas Paramount Leader Deng Xiaoping effected economic reform, via a mixed economy, without weakening the political power of the Chinese Communist Party.