[1] In the late 1950s and early 1960s, Sino-Soviet debates about the interpretation of orthodox Marxism became specific disputes about the Soviet Union's policies of national de-Stalinization and international peaceful coexistence with the Western Bloc, which Chinese leader Mao Zedong decried as revisionism.

[1] In addition, Beijing resented the Soviet Union's growing ties with India due to factors such as the Sino-Indian border dispute, and Moscow feared that Mao was unconcerned about the horrors of nuclear warfare.

[5] The conflict culminated after the Zhenbao Island incident in 1969, when the Soviet Union planned to launch a large-scale nuclear strike on China including its capital Beijing, but eventually called off the attack due to the intervention from the United States.

[13] Historically, the Sino-Soviet split facilitated the Marxist–Leninist Realpolitik with which Mao established the tri-polar geopolitics (PRC–USA–USSR) of the late-period Cold War (1956–1991) to create an anti-Soviet front, which Maoists connected to Three Worlds Theory.

[15] At World War II's conclusion, Stalin advised Mao not to seize political power at that time, and, instead, to collaborate with Chiang due to the 1945 USSR–KMT Treaty of Friendship and Alliance.

Later, ignoring the guidance of technical advisors, Mao launched the Great Leap Forward to transform agrarian China into an industrialized country with disastrous results for people and land.

In response to that discontent among the European members of the Eastern Bloc, the Chinese Communist Party denounced the USSR's de-Stalinization as revisionism, and reaffirmed the Stalinist ideology, policies, and practices of Mao's government as the correct course for achieving socialism in China.

This event, indicating Sino-Soviet divergences of Marxist–Leninist practice and interpretation, began fracturing "monolithic communism" — the Western perception of absolute ideological unity in the Eastern Bloc.

Stalin had accepted that the USSR would carry much of the economic burden of the Korean War, but, when Khrushchev came to power, he created a repayment plan under which the PRC would reimburse the Soviet Union within an eight-year period.

The Soviets opted to publicly support China at the end of August, but became concerned when the US replied with veiled threats of nuclear war in early September and mixed-messaging from the Chinese.

However, political tensions persisted because the economic benefits of the USSR's peaceful-coexistence policy voided the belligerent PRC's geopolitical credibility among the nations under Chinese hegemony, especially after a failed PRC–US rapprochement.

[45][46][41] A number of Communist leaders, including Antonín Novotný, Władysław Gomułka and Shmuel Mikunis, expressed concerns after the meeting, eventually aligning themselves with the Soviet due to the combativeness of Mao's policies.

[52] Moreover, to the Eastern Bloc, Mao portrayed the PRC's warfare with Taiwan and the accelerated modernization of the Great Leap Forward as Stalinist examples of Marxism–Leninism adapted to Chinese conditions.

In turn, Bao Sansan said that the CCP's message to the cadres in China was: "When Khrushchev stopped Russian aid to Albania, Hoxha said to his people: 'Even if we have to eat the roots of grass to live, we won't take anything from Russia.'

[61] In the Romanian capital of Bucharest, at the International Meeting of Communist and Workers Parties (November 1960), Mao and Khrushchev respectively attacked the Soviet and the Chinese interpretations of Marxism-Leninism as the wrong road to world socialism in the USSR and in China.

At the Romanian Communist Party Congress, the CCP's senior officer Peng Zhen quarrelled with Khrushchev, after the latter had insulted Mao as being a Chinese nationalist, a geopolitical adventurist, and an ideological deviationist from Marxism–Leninism.

To Mao, Khrushchev had lost political authority and ideological credibility, because his US-Soviet détente had resulted in successful military (aerial) espionage against the USSR and public confrontation with an unapologetic capitalist enemy.

[74][75] North Korea under Kim Il Sung also remained neutral because of its strategic status after the Korean War, although it later moved more decisively towards the USSR after Deng Xiaoping's Chinese economic reform.

Moreover, the break with the USSR allowed Mao to reorient the development of the PRC with formal relations (diplomatic, economic, political) with the countries of Asia, Africa, and Latin America.

[68] In the 1960s, the Sino-Soviet split allowed only written communications between the PRC and the USSR, in which each country supported their geopolitical actions with formal statements of Marxist–Leninist ideology as the true road to world communism, which is the general line of the party.

[81] To regain political supremacy in the PRC, Mao launched the Cultural Revolution in 1966 to counter the Soviet-style bureaucracies (personal-power-centres) that had become established in education, agriculture, and industrial management.

[98] On 16 October 1964, the PRC detonated their first nuclear bomb, a uranium-235 implosion-fission device,[99] with an explosive yield of 22 kilotons of TNT;[100] and publicly acknowledged the USSR's technical assistance in realizing Project 596.

[111] The United States authorities subsequently informed certain US news media regarding the possible Soviet attack, and the latter made the reports public on August 28 and the following days.

[113][120][121] Over 940,000 soldiers, together with more than four thousand planes and over six hundred ships received evacuation order, while important documents and archives were relocated from Beijing to southwest region of China.

[120] Despite the border demarcation remaining indeterminate, the meetings restored Sino-Soviet diplomatic communications, which by 1970 allowed Mao to understand that the PRC could not simultaneously fight the US and the USSR while suppressing internal disorders throughout China.

[131][132] To facilitate social acceptance of such cultural revisionism, the Soviet press misrepresented the historical presence of Chinese people – in lands gained by the Russian Empire – which provoked Russian violence against the local Chinese populations; moreover, politically inconvenient exhibits were removed from museums,[131] and vandals covered with cement the Jurchen-script stele, about the Jin dynasty, in Khabarovsk, some 30 kilometres from the Sino-Soviet border, at the confluence of the Amur and Ussuri rivers.

[135]: 93  The pro-Soviet group led by Lê Duẩn eventually developed momentum, especially as China sought to improve its relations with the United States, which Vietnamese leadership viewed as a betrayal of the China-Vietnam relationship.

As reactionary political radicals, the Gang of Four argued for regression to Stalinist ideological orthodoxy at the expense of internal economic development, but soon were suppressed by the PRC's secret intelligence service.

[138] The re-establishment of Chinese domestic tranquility ended armed confrontation with the USSR but it did not improve diplomatic relations, because in 1973, the Soviet Army garrisons at the Sino-Soviet border were twice as large as in 1969.

[161][162] The meeting took place right before the Tiananmen Square Massacre in June 1989, for which the Soviets expressed diverging opinions at many levels, from the official rhetoric, to media coverage and to the public reaction.