‘You [the Soviet Union] piss on my head and I should respect you?’ Mao observed gravely. He was speaking to a visiting communist leader, Romania’s dictator Nicolae Ceauşescu, who was trying, in his usual self-promoting fashion, to mediate between Beijing and Moscow. Mao would have none of it. ‘No matter who tries to persuade us [to mend fences], we won’t move,’ he said. ‘The more they talk the worse relations will become.’

The two communist giants had been at one another’s throats for more than a decade. What seemingly began as polemics over obscure doctrinal differences eventually evolved into a fully-fledged confrontation, armies and all, with the Soviets dropping hints of nuclear obliteration and the Chinese digging tunnels under Beijing. In 1969 the two countries fought several border skirmishes; they later managed to at least begin a tentative conversation, but Mao wasn’t willing to go beyond cold formalities. The Soviet Union was the enemy. The Soviets were ‘pissing on his head’.

Mao had an outsize impact on China’s relationship with the Soviet Union. He was the one who turned China towards an ideological alignment with Moscow. He, too, was the one who later quarrelled with his Soviet comrades. Now, given an opportunity to steer the relationship towards a rapprochement, he refused. China and the Soviet Union remained enemies for the rest of the decade, even well into the early 1980s. It wasn’t all Mao’s fault, but if one were to look for reasons for the Sino-Soviet split, Mao Zedong’s grievances and fears, his delusions and his ambitions would surely number among key factors that a historian would have to consider in reflecting on the ups and downs of the thorny relationship. Mao’s role was in fact so profound that it offers a useful starting point for generalising about leadership and statesmanship in an authoritarian context, and for drawing lessons for the present state of Sino-Russian relations, which, too, are characterised by outsize roles played by individual personalities.

‘Before I met with Stalin,’ Mao recalled some years after the Soviet dictator’s death, ‘I did not have much good feeling about him… He was very different from Lenin: Lenin shared his heart with others as equals whereas Stalin liked to stand above everyone else and order others around.’

A guerrilla, a philosopher, a survivor of the Long March and the trials of the Chinese Civil War, Mao emerged at the end of the 1940s as China’s undisputed leader. Yet, by virtue of his ideological inclinations, Mao was from the start committed to a relationship with Moscow, and – much as he disliked the idea – was willing to subordinate himself to the centre, to Stalin himself. He understood that the wily dictator never fully trusted him.

Stalin had a particular resentment of self-made Communists like Mao. Just two years before the Communist revolution in China, Stalin broke with Josip Broz Tito of Yugoslavia (he was jealous of Tito’s ambitions in the Balkans). Soviet relations with Yugoslavia nosedived and the two countries edged to the point of an outright war (while Stalin secretly planned to have Tito poisoned). Mao knew that Stalin regarded him as at least a potential Chinese Tito, and worked hard to reassure him. He proclaimed himself a loyal pupil of Stalin’s and declared, in a newspaper editorial in June 1949, that China would ‘lean to one side’ – the Soviet side.

In December 1949 Mao travelled to Moscow. It was a trip that eventually resulted in the signing of the Sino-Soviet treaty of alliance. But it did not go particularly well. In fact, Stalin refused to sign the treaty at first, sending Mao to cool his heels at a dacha outside Moscow, where the latter nurtured his wounded pride and steamed in quiet fury. It was not very clear – neither then, to Mao, nor to historians who followed the documentary trail – why Stalin would do such a thing. The best explanation is that Stalin was worried – still very worried – about the prospect of American intervention in the Chinese Civil War. Only when these fears were allayed, or perhaps after he became worried that Mao’s resentment would drive him towards the West, did Stalin change his mind and give Mao his treaty.

Even as he did, he attached multiple conditions and secret clauses, which Mao would later call ‘bitter fruits’. Some of these – for instance, the one about joint ownership of the trans-Manchurian railroad and joint enterprises in China – were blatantly neocolonial in character. Mao swallowed his pride. For him, allying with the Soviet Union was an exceptionally important foreign policy move that linked back to his revolutionary plans at home. He wanted to transform China. For this, he needed Stalin’s help. And it came – in the form of advice, weapons, technologies, experts and, yes, an actual treaty of alliance.

‘The Russian and the Chinese are brothers forever’ ran a popular propaganda song of the early 1950s. ‘The unity of the peoples and races is becoming stronger. The common man stands with his shoulders straight. The common man is marching with a song. Stalin and Mao are listening to you.’ Yet for all the outward signs of vitality – and at the time the alliance certainly projected internal strength and external menace – all was not well. Later, Mao would grumble ceaselessly about his relationship with Stalin being like that between ‘a cat and mouse’ or between ‘a father and son’. He was willing to defer to Stalin while Stalin was alive. Mao considered the socialist bloc to be something like a family, but it was a family that lacked true love – just grudging respect. Mao respected Stalin the way a filial son would respect his distant father. The dictator’s death in 1953 changed everything.

Stalin’s eventual successor, Nikita Khrushchev, was, in Mao’s considered view, an upstart. Unlike Stalin, a revolutionary leader and (however crude) a theorist of Marxism-Leninism, Khrushchev had not distinguished himself in any way that would impress the Chinese leader. Yet when Khrushchev reached the pinnacle of power in the mid-1950s, Mao offered his support. What he expected in return was a degree of deference to Mao’s strategic outlook. Mao believed himself to be much better placed than Khrushchev to pass judgements on profound matters such as war and peace and the future of revolution.

Khrushchev did not see things this way. Although he initially sought Mao’s approval – his very first foreign visit as a leader was to China, for the fifth anniversary of the establishment of the People’s Republic of China in 1954, – he also grew to resent Mao, who he increasingly considered unbearably arrogant. Khrushchev did not consult with the Chinese leader when he decided, in February 1956, to speak out against Stalin at a closed session of the Twentieth Party Congress. That speech – and the broader ‘de-Stalinisation’ campaign – unsettled Mao. He cautioned the Soviets that Stalin had been a great Marxist-Leninist who, though he had committed a few mistakes (in Mao’s estimation – mostly relating to his China policy), nevertheless remained a revolutionary leader, whose legacy underpinned the entire socialist project. When later that year unrest engulfed Poland and Hungary, Mao was confirmed in his worst fears.

Some Chinese historians today consider Khrushchev’s de-Stalinisation the beginning of the Sino-Soviet split. In this reading, it was Mao’s ideological disagreement with Khrushchev – over issues like Stalinism, or theoretical questions of war and peace – that laid the ground for the break-up of the alliance. Ideology was an important part of the relationship. One could interpret the ideological quarrel purely instrumentally – i.e. as a way to rationalise disagreements that developed for other reasons – but it seems that it played a more profound role, certainly in Mao’s case.

This was because Mao (who saw himself as something of a great philosopher, though he despised intellectuals) internalised the arguments he was presently flinging at the USSR: that Khrushchev was a ‘revisionist’; that he betrayed the revolution; and that China’s own revolutionary future depended on its ability to stand up for true Marxism. In other words, Mao linked the Sino-Soviet relationship with the fate of the Chinese revolution.

This does not, however, tell the entire story, or even half the story. Mao clearly resented the relationship with the Soviet Union because it was inherently unequal. It was a relationship where the Soviet Union was the ‘older brother’, whose dictates Beijing was expected to embrace with obedience and even enthusiasm. Mao, with his own unsatisfied ambitions of leading China to greatness, could not accept such a hierarchy.

During one infamous encounter with the Soviet ambassador (which followed a Soviet proposal to build a joint submarine fleet), Mao let out a stream of invective that betrayed the depth of his anger with Moscow: ‘You never trust the Chinese!’ he bellowed. ‘You only trust the Russians! [To you] the Russians are the first-class [people] whereas the Chinese are among the inferior who are dumb and careless.’ The ambassador, surprised by such an unexpected onslaught, anxiously reported it to Moscow, and Khrushchev urgently flew to China to reassure Mao that he never meant to suggest anything so vaguely neocolonial as a joint submarine fleet.

Tensions did not dissipate. Khrushchev was angered by Mao’s failure to consult when, in late August 1958, the Chinese launched an artillery barrage against the Taiwanese-held islands just off the Chinese coast. That action, which led to the so-called Second Taiwan Strait Crisis, risked entrapping the USSR in a superpower confrontation in spite of Khrushchev’s best intentions. For his part, Mao became furious when Khrushchev adopted a neutral attitude in the 1959 Sino-Indian border skirmish. For him, failing to side with China reeked of a betrayal of an ally in need. Khrushchev’s flirtation with the United States greatly annoyed Mao. In September 1959 Khrushchev made his maiden voyage to the United States for meetings with President Dwight D Eisenhower, and then turned up in China and attempted to pressure Mao to release US citizens held in Chinese detention. The meeting between Mao and Khrushchev, and their lieutenants, at one point became so tense that the Soviet leader began shouting and even told the Chinese foreign minister Chen Yi to stop spitting at him: ‘You do not have enough spit!’

Khrushchev left China in great agitation, never to return. The Sino-Soviet relationship went rapidly from bad to worse. Soon, Khrushchev, in a blatant attempt to put his ally under economic pressure, tore up all aid contracts and recalled Soviet experts working in China. Mao remained uncowed. He regarded Khrushchev as a fool and a bully, and was determined to push back.

Mao’s deep personal dislike of Khrushchev and his resentment of the Soviet Union (fully reciprocated by the Soviets) led to a rapid unravelling of an alliance that was only recently deemed eternal and unbreakable. Beijing and Moscow increasingly perceived one another as rivals and began to compete fiercely for the hearts and minds of the revolutionary world. China made few gains, for, despite Mao’s rhetoric, it had little to offer far-flung guerrilla movements and struggling socialist regimes. It was desperately poor itself and, for a period in the early 1960s, found itself in the depths of the worst man-made famine in world history. Yet China’s challenge in what was then called the Third World (the precursor to today’s Global South) seriously worried Khrushchev.

Another worry of Khrushchev’s was China’s unexpected challenge to the Sino-Soviet border. Border tensions began to build up in the early 1960s. Beijing and Moscow agreed to border talks, which proceeded well until, in July 1964, Mao decided to torpedo them by declaring, in a meeting with Japanese socialists (who released this information to the public), that China was robbed of vast territories by the Russian tsars and that Beijing was yet to present a bill for the offence.

Khrushchev was outraged. ‘Have you read the hideous document about the border?’ he asked his colleagues. ‘I read it yesterday and became indignant.’ The Chinese, he continued, were ‘evil, hypocritical, crafty and cunning’, citing no less an authority than the 19th-century Russian explorer and spy Nikolay Przhevalsky, who had left many a racist reflection on China in his voluminous writings. ‘It is completely evident that this is a person who has lost his mind,’ Khrushchev commented disparagingly.

It is difficult to know – even today – why Mao raised the question of the lost territories. It is conceivable that he wanted to use the territorial non-issue (for it had not been an issue until then) to sabotage the improvement of Sino-Soviet relations, because any such improvement would be inconsistent with his plans for China’s revolutionary transformation. This domestic-centred explanation has much to it. Indeed, within two years Mao unleashed his so-called Great Proletarian Cultural Revolution, which had a distinct anti-Soviet component. Or it could have been an unplanned jab at Khrushchev (whom Mao deeply despised).

Even Khrushchev’s ouster in October 1964 failed to reverse the waning fortunes of the Sino-Soviet alliance. When the new Soviet prime minister Aleksei Kosygin turned up in Beijing to plead with Mao to forget old quarrels and start from a clean slate, the Chinese leader told him, mockingly, that Sino-Soviet disagreements would last for 10,000 years. When Kosygin called for shortening the time, Mao agreed to drop 1,000 years but no more.

Tensions between the two countries continued to increase until, in March 1969, border skirmishes broke out over a small disputed islet of Zhenbao on the River Ussuri, which separated the two countries in the far east. Worried about a fully fledged war with their neighbour, the Soviets made half-hearted moves towards rapprochement. Mao, though, remained adamantly opposed to mending fences. Instead, he reached out to the Americans. In 1970 he confided to a visiting US journalist, Edgar Snow, that he thought Richard Nixon was ‘the No. 1 good fellow in the world’. The transcript of this conversation was forwarded to the party faithful across the country, and caused a great deal of confusion: how could the leader of American imperialism (hitherto daily vilified by Chinese propaganda) turn out to be ‘the No. 1 good fellow in the world’?

But such was Mao’s political power that he could overturn ideological taboos and quickly turn around the ship of state, and with hardly any need to consult his comrades, never mind the country. It was thus that he effected the Sino-American rapprochement and, for most intents and purposes, took China out of the Cold War. Revolution was out. Development was in.

Beijing and Moscow mended fences – eventually. Relations began to thaw in the early 1980s, with Mao safely out of the picture (he died in 1976). There is a good reason why that had to be so. Mao’s hatred of the Soviet Union was so profound that it was quite inconceivable that he could have put all that enmity aside and embraced his former comrades, now enemies. He became personally invested in the Sino-Soviet split, and he showed no interest in reversing course.

Sino-Soviet relations were fully normalised only in 1989, with Mikhail Gorbachev’s trip to Beijing (a full 30 years after Nikita Khrushchev’s last quarrelsome encounter with the Chinese leaders). Mao’s heir and successor Deng Xiaoping (who, in his time, took a most direct and active part in splitting with the Soviet Union) told Gorbachev that the time had come to ‘close the past and open the future’.

That future turned out to be much more auspicious than the past. Although the collapse of the Soviet Union and the emergence of a new – and briefly ‘democratic’ – Russia unsettled the Chinese leaders, they quickly recognised the new reality and embraced Russia as a partner.

The relationship became ever tighter in the years that followed. There was, for once, an understanding across the policy-making elites in both Beijing and Moscow that they had to do everything to avoid a repetition of the disastrous confrontation that proved so costly, and that only benefited third parties (ie, the United States).

China and Russia were, after all, natural partners – certainly economically (with Russia becoming a key supplier of energy), but also politically. It is that latter element in particular – political alignment – that became increasingly evident as Xi Jinping rose to power in China. Xi and Russian president Vladimir Putin shared a worldview: a similar set of grievances about their countries’ positions in the world pecking order, and an ambition to change the global balance of power in a way that would favour their states. Unlike Mao and Stalin in their time, they were not themselves locked in a hierarchical relationship.

This was an alignment, not an alliance. It was much more flexible, much more responsive to their needs. It was most certainly not ideological.

Yet there also appeared a continuity. As in the 1950s, Xi and Putin, presiding over two autocratic regimes, endowed with immense powers of coercion and seemingly unconstrained by institutional checks and balances, hold the fate of this relationship in their hands. China and Russia are vast countries that interact at multiple levels: political, economic and social, national and regional. But it is the personal relationship between Putin and Xi that defines the overall direction. Their grievances and hopes give state-to-state relations a meaning that they would not otherwise have. Understanding their personal interaction – still shrouded in secrecy – is important for deciphering the future trajectory of the Sino-Russian relationship.

Will the Russians and the Chinese again become ‘brothers forever’, as in that song from the early 1950s? And how will the two dictators at the helm of great empires navigate their jealousies and their insecurities? The final verse of this song is still to be written.