Whether you like it or not, history is on our side. "We will bury you!" Thus in 1956 did Nikita Khrushchev, then first secretary of the Communist Party of the Soviet Union, predict the future.
Xi Jinping is far more cautious. But his claims, too, are bold. "Socialism with Chinese characteristics has crossed the threshold into a new era," the general secretary of the Communist Party of China told its 19th national congress last week. "It offers a new option for other countries and nations who want to speed up their development while preserving their independence." The Leninist political system is not on the ash heap of history. It is, yet again, a model.
Mr Krushchev's claim seems ridiculous now. It did not seem so then. The industrialisation of the Soviet Union had helped it defeat the Nazi armies. The launch of Sputnik in 1957 indicated it had become a technological rival for the United States. Yet 35 years after Mr Krushchev's boast, the USSR, the Soviet Communist Party and its economy had collapsed. This remains the most extraordinary political event since World War II. Meanwhile, the most remarkable economic event is the rise of China from impoverishment to middle-income status. That is why Mr Xi is able to talk of China as a model.
Yet how has the system that failed in Moscow succeeded in Beijing? The big difference between the two outcomes lay with Deng Xiaoping's brilliant choices. China's paramount leader after Mao Zedong kept the Leninist political system - above all, the dominant role of the Communist Party - while freeing the economy. His determination to maintain party control was made clear by his decisions during what the Chinese call the "June 4 Incident" and Westerners the "Tiananmen Square massacre" of 1989. Yet his resolve to continue with economic reform never faltered. The results were spectacular.
Whether the Soviet Union could have followed such a path is open to debate. But it did not. As a result, today's Russia does not know how to mark the October revolution of a century ago: President Vladimir Putin is an autocrat, but the communist system has gone. Mr Xi is also an autocrat. His dominance over party and country was on display at the party congress. But he is also an heir to the Leninist tradition. His legitimacy rests on the party's.
What are the implications of China's marriage of Leninism and market? China has indeed learnt from the West in economics. But it rejects modern Western politics. Under Mr Xi, China is increasingly autocratic and illiberal. In the Communist Party, China has an ostensibly modern template for its ancient system of imperial sovereignty and meritocratic bureaucracy. But the party is now emperor. So, whoever controls the party controls all. One should add that shifts in an autocratic direction have occurred elsewhere, not least in Russia. Those who thought the fall of the USSR heralded the durable triumph of liberal democracy were wrong.
Will this combination of Leninist politics with market economics go on working as China develops? The answer must be: We do not know. A positive response could be that this system not only fits with Chinese traditions, but the bureaucrats are also exceptionally capable. The system has worked spectacularly so far. Yet there are also negative responses. One is that the party is always above the law. That makes power ultimately lawless. Another is that the corruption Mr Xi has been attacking is inherent in a system lacking checks from below. Another is that, in the long run, this reality will sap economic dynamism. Yet another is that as the economy and the level of education advance, the desire for a say in politics will become overwhelming. In the long run, the rule of one man over the party and that of one party over China will not stand.
All this is for the long run. The immediate position is quite clear. China is emerging as an economic superpower under a Leninist autocracy, controlled by one man. The rest of the world has no choice but to cooperate peacefully with this rising power. Together, we must care for our planet, preserve peace, promote development and maintain economic stability. At the same time, those of us who believe in liberal democracy - the enduring value of the rule of law, individual liberty and the rights of all to participate in public life - need to recognise that China not only is, but sees itself as a significant ideological rival.
The challenge occurs on two fronts.
First, the West has to keep a margin of technological and economic superiority, without developing an unduly adversarial relationship with Mr Xi's China. China is our partner. It is not our friend.
Second and far more important, the West (fragile as it is today) has to recognise - and learn from - the fact that management of its economy and politics has been unsatisfactory for years, if not decades. The West let its financial system run aground in a huge financial crisis. It has persistently under-invested in its future. In important cases, notably the US, it has allowed a yawning gulf to emerge between economic winners and the losers. Not least, it has let lies and hatred consume its politics.
Mr Xi talks of the "great rejuvenation of the Chinese nation". The West needs rejuvenation, too. It cannot rejuvenate by copying the drift towards autocracy of far too much of today's world. It must not abandon its core values, but make them live, once again. It must create more inclusive and dynamic economies, revitalise its politics and re-establish anew the fragile balance between the national and the global, the democratic and the technocratic that is essential to the health of sophisticated democracies. Autocracy is the age-old human norm. It must not have the last word.