Ai Weiwei is talking me through the decision-making process before his first visit to China in over a decade. The artist, known around the world as the most famous critic of the Chinese communist regime, had to do some fraught arithmetic before deciding to head back home.

Before boarding a flight with his son, who had never met the artist’s elderly mother, Ai thought back to his time in detention when his captors told him he would spend the next 13 years in custody on bogus charges: “They said, ‘When you come out, your son won’t recognise you.’ That was very heavy and really the only moment that touched me.”

He ended up spending several months in captivity. Lao, his son, is now 17. Ai says Lao doesn’t really need his guidance any more so he decided to book their flights and roll the dice. “People said, ‘Are you scared?’ I said, ‘No, why should I be scared?’ I’m Chinese. I have a Chinese passport. I’m entitled to go back and see my mum. So I went back.”

Welcome to the life of Ai Weiwei. For most people, returning home doesn’t involve weighing up the risk of whether you’ll see close family ever again, but that’s the reality for a 68-year-old whose whole existence has been shaped by authoritarianism and the struggle against it.

His trip to China went well. He ended up being interviewed at the airport and released after a couple of hours into a country whose smells, sights and sounds were soothing to him. Ai described the journey as being like “a phone call suddenly reconnecting”. Today, he’s more poetic, describing it as “a piece of jade broken that you can put back together because it matches very well. Everything’s so familiar: the light, the temperature, the people.”

Ai is meeting me in the London offices of his publisher to talk about his new book, On Censorship, a 90-page polemic on the nature of state control, AI and surveillance. The man certainly knows about these things. Born in Beijing in 1957, he grew up in labour camps in north-west China following the exile of his father, the poet Ai Qing. In 2011, he was detained for 81 days in a 170 sq ft windowless prison because of his own activism. Upon his release, he was tracked, interrogated and threatened by the Chinese state; then his passport was returned in 2015 and he began a life in exile. He currently divides his time between Lisbon, Berlin and Cambridge.

His artworks are as dramatic as his backstory. An army of 1,600 Chinese artisans created 100m hand-painted porcelain “seeds” that were scattered over the floor of Tate Modern’s Turbine Hall in London 16 years ago. He cloaked Berlin’s Konzerthaus in 14,000 fluorescent orange lifejackets worn by refugees; and made a film dedicated to the children who died in the 2008 Sichuan earthquake. That direct challenge to the official state narrative made him “the most dangerous person in China”.

His upcoming work, at Aviva Studios in Manchester, involves 30 tonnes of buttons, which were saved from a London factory that was closing down and smuggled into China to be turned into huge hanging artworks by craftspeople.

The book is a startling read, arguing that those in the west misunderstand the nature of censorship. He defines it as “the exercise of power over intellectual space”, both “an indispensable tool of mental enslavement and a fundamental source of political corruption”. It is not just authoritarian regimes, he warns. Liberal societies think that censorship is rare, “but people forget that even on sunny days, shadows are inevitable”.

Some of the arguments are perplexing. In a section about the limitations of AI, the artist refers to the selfie he took with AfD leader Alice Weidel in 2018. He says AI decided that the image, which is real, must have been fake because the pair seemed to be on opposite ends of the political spectrum. At the time of the selfie, Weidel, whose grandfather was a Nazi, was considered to be in the more moderate wing of the far-right party, but since becoming leader has called for “large-scale repatriations” of foreigners, saying the country’s focus on the Holocaust is akin to a “guilt cult”.

Does Ai regret the selfie? He tells me that on many issues, her political demands “could be wrong”, but she’s still “more rational than other political opponents in Germany”. What about her anti-immigrant rhetoric – isn’t that anathema to him? “Some states don’t even accept one [immigrant] and Germany accepts 1.2 million, which is a pretty generous decision,” he replies. “So if they change the policy and they want to limit it, then there is nothing wrong.”

He’s also impressed by the fact that Weidel “openly wants Germany to be more independent from American influence”. He adds: “I think those are some of the things that we need to do.” Those who know German politics would find that argument surprising because the AfD are seen as the party who are closest to Trump and nearly all parties in the country want more independence from the US. A ringing endorsement of someone at the outermost reaches of far-right European politics might cause a few double takes, and there are more surprises.

Ai’s attitude to China has shifted dramatically. The nation, he said recently, is “in an upward phase,” pointing to the technological advancements made and increased personal freedoms. The west, however, struggles to “sustain its own logic”, has lost its “ethical authority” and has “descended into something barely recognisable”.

Although a quick glance across the Atlantic at America in the age of ICE raids does somewhat make his point, he means Europe, too. So is the Chinese regime’s most famous critic now toeing the party line? “My position with China started before I could recognise myself as an individual. I grew up in this black hole with my father,” he says, pointing to a picture on his iPhone of a desolate location in north-west China.

He’s not angry exactly, but the suggestion that he’s softened on the Chinese government has touched a nerve. “I still have a Chinese passport. My mum is still Chinese. So that’s my only relationship to China,” he says. “I’m not nostalgic. I’m not patriotic.” What about the claim that the west embraces censorship? Is that his experience in the UK? “I cannot get into details,” he says cryptically. “But I feel the same kind of surveillance, same kind of censorship in the west.”

Pressed for an example, he tells me a story about the Royal Academy in London, an institution that gave him a landmark exhibition in 2015 and made him an honorary member in 2011 following his detainment in China. In November 2023, an exhibition of new works to be shown at the Lisson Gallery was pulled after he posted a tweet that began: “The sense of guilt around the persecution of the Jewish people has been, at times, transferred to offset the Arab world.” The tweet was deleted, with the artist telling journalists his show had “effectively [been] cancelled”.

In the aftermath, a vote was then held at the RA to determine whether his membership should be revoked because of accusations that the post was antisemitic. “I don’t have the intention of an antisemite. My best friends, they’re all Jewish people,” says Ai. “I tweeted millions of tweets on Twitter, but [how is it that] this tweet can cause such trouble? Then they said the procedure is to let the Academicians vote.”

His peers supported him and he won the vote. Ai was then asked to write an article about freedom of speech for the RA’s magazine, which he did, arguing: “Speaking the truth and insisting on one’s own perspective is dangerous and may come at a heavy price. Books may go unpublished, exhibitions may be closed, concerts cancelled.”

After he sent it, there was silence. Then he says the RA claimed they didn’t have room to run the piece. For him, this is the censorship in the west, which he argues in On Censorship can be “more covert, more deceptive and more corrosive” than in authoritarian regimes. “I have several cases like this,” Ai adds. “Happens in Britain and in Germany.”

The RA disputes this account, claiming the decision to drop the piece was made before Ai submitted it. A spokesperson added: “Plurality of voices, tolerance and free thinking are at the core of what we stand for and seek to protect.”

I wonder how Ai feels about the world in 2026. His new book paints it as a place without refuge for those who value self-expression and freedom of speech. “I think today we are living in a complicated world, where life is more like a shattered mirror,” he says. “It reflects the reality, but the reality can be a broken reality.”

Did his trip to China restore his faith in humanity? There’s a pause. “If we were in the time of the Tang dynasty, someone like me would go back and write beautiful poetry,” he says, smiling. “But not today. I just take a few selfies.”

• On Censorship by Ai Weiwei is published by Thames & Hudson (£12.99). To support the Guardian, order your copy at guardianbookshop.com. Delivery charges may apply.