'No one can stop the wheel of history," said China's President Xi Jinping on the recent 75th anniversary of the day when the Chinese Communist Party (CCP) proclaimed the creation of the People's Republic of China. And the wheel is indeed still turning -- but that may not be good news for the fourth-generation heirs of that revolution.
The 1950s was the time of peak Communism, when people still feared or hoped that it would spread across the whole world. That was never likely, however, and apart from Cuba and Vietnam, it never spread any farther.
The Soviet Union itself finally evaporated peacefully in 1991 at the age of 74, taking the rest of the European Communist regimes down with it.
At that point, China suddenly became the world's oldest surviving Communist state -- which had the same psychological impact on the CCP as losing one's own parents does to those in the middle generation. Suddenly, your own generation is on the front line, with personal extinction waiting for you down the road.
The Chinese Communist revolution was still only 42 years old in 1991, of course, but a chill wind began to blow as Party members realised that Communist regimes can be mortal too. From that time on, avoiding the fate of the Soviet Union has become the unwritten subtext of almost every major policy decision the CCP regime has made.
Inevitably, there were competing prescriptions for the best way to avoid that fate. By the middle 1990s, two dominant strategies had emerged, espoused by two rival factions: the "princelings", who were the children and grandchildren of the founding revolutionary heroes, and the "populists", who had risen by merit.
Most "populists" had grown up poor somewhere in the country's vast interior and were aware of the needs of vulnerable social groups like farmers, migrant workers and the urban poor. Their formula for outlasting the Soviet Union was a more generous welfare state, more open media, and more democracy within the Party.
Most of them came up through the Communist Youth League and were known in Chinese as tuanpai ("the League faction").
The "princelings", by contrast, were born to privilege and rose easily upward through the ranks of the ruling party as they matured. They generally took a more authoritarian and centralising approach to politics, and they regularly pointed out that it was Mikhail Gorbachev's attempt to "reform" the Soviet Communist Party that precipitated its downfall.
However, in the nineties and the noughties the Chinese economy was still growing very fast, and a choice between the rival strategies could easily be postponed. For almost three decades the two factions carefully shared power and never attacked each other in public. But then the economic miracle ran out of steam.
There was really nothing miraculous about China's 30 years of high-speed growth (10% a year). Most industrialising economies get that one-time bonus growth while the rural population migrates to the cities and provides emerging industries with almost limitless cheap labour.
Britain had that in 1850-1880, the United States in 1870-1900, Russia in 1920-1940 (cut short by the Second World War), and Japan in 1950-1980. It never lasts, and China's time was up by 2015.
That's why the truce between the princelings and the populists was broken in 2012-2015, as Xi Jinping, the ultimate princeling, took over all the major offices of state: President of the Chinese People's Republic, and General Secretary of the Chinese Communist Party, and Chairman of the Central Military Commission. It is decided: the future is authoritarian.
There's no surprise in that. The princelings were always a more cohesive faction, and "reform" is seen by most Chinese Communists as the gateway to oblivion. The question is whether repression can be a successful long-term strategy, especially when the economy is no longer growing fast, and the population is going into decline.
We can't really estimate the likely longevity of the kind of high-tech total surveillance state that Mr Xi is building in China now, because it's a new thing in history. It's more ambitious than any previous experiment in controlling human behaviour, and if it works then the regime could turn out to be immortal.
On the other hand, you just have to write that sentence down to realise how implausible it is. The Old Hundred Names have seen off a dozen other dynasties and countless invaders; they're probably not finished yet.