The only Chinese person ever to receive a Nobel prize while living in China, the writer and dissident Liu Xiaobo, was able to spread his democratic manifesto, Charter 08, through the internet. The web, he said, was "truly God's gift to the Chinese people", allowing them to skirt official censorship.

By the time he died last Thursday, the internationally celebrated martyr to democracy must have been despondent at what China's internet had become. In 2014, a political cartoonist published his conception of the Chinese web: A computer keyboard and mouse are chained and taped down, padlocked, while the screen shows only the heavy bars of a prison cell.

Under the unrelenting strictures of the Chinese Communist Party, the internet had become a virtual prison. It was to be Cheng Tao's last political work. "This is my last satirical cartoon," he wrote. "Don't just glance at it: every piece was drawn under immense pressure. I draw and I share at immense risk." His family had pleaded with him to stop antagonising the authorities, he explained. He was giving up. He would henceforth draw entertainment works, he said.

The party's control of the web has only continued to intensify since. Confounding all predictions by Western tech experts, it has been extraordinarily successful in censoring the internet, guiding the public agenda and eliminating dissent.

One indicator of the party's success was that, on the weekend, China's web censors banned Winnie the Pooh. The name and images of the cartoon bear were being systematically removed because he had become too politically sensitive.Why? "While no official explanation was given, observers suggested the crackdown was related to previous comparisons of President Xi Jinping with the portly bear," reports Yuan Yang of The Financial Times. It was nothing sinister. Xi was likened to the fictional character because they are both round-bellied and benign-looking. But censorship of political debate has become so thoroughgoing that the authorities don't merely repress dissent or criticism but even subtle references and symbols.

As the British paper quotes a Chinese media expert, Qiao Mu, of Beijing Foreign Studies University, as saying: "Historically, two things have been not allowed: political organising and political action. But this year a third has been added to the list: talking about the President." Even through cartoon allusions.

It may seem ridiculous, but for the Chinese Communist Party this is deadly serious. Nothing is more important than "stability maintenance", meaning the preservation of the party's monopoly on power. A key reason that China's Communist Party is the most durable authoritarian regime on earth is that there is no alternative. No one has been able to create any national organisation that could conceivably turn its hand to politics. This is a reason that the Falun Gong, or Falun Dafa, movement was so ruthlessly repressed. Not because it was political - its emphasis is on spiritual meditation - but because it had a national organising structure.

Any of its remaining sympathisers who try to use the web to communicate covertly are subject to "increasing electronic surveillance", says researcher Sarah Cook of the US-based Freedom House, with authorities "deploying geolocation technology to find and arrest them". The internet has been turned from an instrument of possible organisation into a tool of repression.

The authorities are not content to police any hint of dissent. They create a thriving universe of pro-regime, pro-party and nationalist messages. Or as Harvard sociology professor Gary King puts it, the party pursues "cheerleading for the state" as "strategic distraction". It is, in Beijing's planning, just the beginning. The party has declared that its increasing power in the world will soon be matched by its power over global "discourse".

The era of "Western strength and Chinese weakness" is at an end, says a senior official at the Central Party School, the institution that trains Communist Party cadres, executive vice-president He Yiting​. He wrote in a party journal, quoted by the China Media Project at Hong Kong University: "Not too far off in the future, China's dominance in terms of development, institutions and governance will be transformed into discourse dominance on the international stage. The Chinese era of international discourse is at our doorstep."

And the thrust of that discourse? He is not talking about fun stuff like Chinese film, cuisine or literature. He explains: "The most important thing here is that the great rejuvenation of the Chinese nation is owed to the leadership of the Central Party with comrade Xi Jinping as the core, and the rejuvenation of Chinese discourse is led by the series of important speeches made by General-Secretary Xi Jinping."

Unlike the cartoonist Chen, the democracy activist Liu Xiaobo never gave up. Through a cumulative total of 12 years in jail in four separate incarcerations, he remained committed to non-violent political change. Which is why he died of liver cancer last week in the same circumstances in which he received his Nobel Peace Prize in 2010 - in detention.

Xi Jinping is consolidating yet more power in the approach to the five-year party congress to be held late this year. He controls the "discourse" and Liu is not part of it. Liu is a hero in the West but almost entirely censored out of existence in China. Ordinary Chinese do not know his name. Even the phrase "rest in peace" has been comprehensively scrubbed from China's internet since his death. There is no point in deluding ourselves. The authoritarian project is succeeding in China, just as the West's confidence in its own democracy is failing.

Peter Hartcher is international editor.