At the age of 20, and already a war-worn pro-democracy activist, Joshua Wong would stand to attention in a courtyard each morning and shout: “Good morning, sir! I, Joshua Wong, prison number 4030XX, have been convicted of unlawful assembly. Thank you, sir!”

His school classmates would hardly have picked him as the one most likely to be eating prison food before their 21st birthday. Scrawny and bespectacled, in his teens he was known as a “dokuo” – a Japanese term for a socially awkward young lad who has no luck in love and just longs to be left alone among his video games and gadgets.

But there was always something different about Joshua, the son of two devout Christians who brought him into a politicised home. His parents married in Hong Kong in the spring of 1989, just after the Chinese government sent in tanks to crush the student demonstrators on Tiananmen Square. Deciding to abandon their arrangements for an elaborate wedding celebration, they sent out handwritten notes to their friends and relatives saying: “Our nation is in crisis, the newlyweds shall not stand on ceremony.”

Their son, who was born a few months before the British handed their Hong Kong colony back to Beijing, inherited the political gene. At 17, his face – “The face of protest” – was on the cover of Time magazine, and he was ranked among the world’s 10 greatest leaders. A few years later he was nominated for a Nobel Peace Prize.

Wong is detained by police during an attempt to intercept the motorcade of top Chinese official Zhang Dejiang on May 19th, 2016 in Hong Kong. Photograph: Handout/Getty Images Unfree Speech: The Threat to Global Democracy and Why We Must Act Now, co-written with lawyer and writer Jason Y Ng, tells Wong’s story. It’s a memoir that explores how he went from schoolyard nerd to democracy superhero, as he was also portrayed in a Netflix documentary.

It is a call to arms to the Instagram generation, a manifesto aimed at the youth all over the world to engage in bottom-up resistance to hold the ruling classes to account.

Wong is inspired by other young activists such as Greta Thunberg and Malala, and grassroots movements such as Extinction Rebellion and the post-Parkland gun-law campaign, increasingly led by millennials and Generation Zers, “as they are often the ones most impacted by older generations’ inaction and acquiescence”.

Crusader Diagnosed with dyslexia in his early years, he focused on the spoken word to articulate himself. As a child he was always itching to take centre-stage when his father addressed Christian congregations, seeing the microphone as his weapon of choice in life, “like Thor’s hammer of Captain America’s vibranium shield”.

His religious beliefs made him convinced from an early age he was a crusader – someone put on this world to take action against injustice whenever he encountered it.

His first mortal enemy: school dinners.

As a 12-year-old he combined his oratorical and social media skills to co-ordinate a prolonged campaign, in which he ultimately triumphed, to eject the college caterers and bring in new cooks.

Still not sated, he spent much of that pre-teen summer reading about his city’s bizarre electoral system that seemed to him designed to help government stonewall any opposition or dissent.

The conclusion he came to was the mess left behind was “the product of numerous painful – some say callous – concessions made by Britain during the handover negotiations with China”.

So many of Hong Kong’s woes, he found, were attributable to a single culprit: unaccountable government and the lopsided electoral system that created and facilitates it. Tackling this became an early obsession.

Mass marches and violent demonstrations have roiled the city for the past eight months

Trusty microphone in hand, at 14 years of age he found himself leading an angry 100,000-strong crowd after the government tried to introduce pro-Beijing, patriotic values into the school curriculum. Arguing it was nothing more than a move to indoctrinate the city’s children, he forced the government to back down in the face of well-orchestrated opposition.

It was a rare political defeat for the establishment, and blooded Wong and the city’s youth for the Umbrella Revolution in 2014 – a pro-democracy protest movement that brought much of central Hong Kong to a standstill for three months.

Wong got his first prison sentence for his involvement in those protests, and he jokes there were often enough members of his political party in prison to have a quorum for a committee meeting.

While the movement failed to achieve its aims, it brought about a real political awakening in the city and gave Wong’s generation new confidence to challenge Communist China.

When mass protests began to flare up in June last year over a plan to introduce a Bill that would allow extradition to China, it felt to Wong as if it was the Umbrella Movement all over again, except this time protesters were angrier and more combative than their predecessors.

Mass marches and violent demonstrations have roiled the city for the past eight months as pro-democracy protesters and police engage in ongoing street battles. A common piece of anti-government graffiti seen around the city offers one explanation for the escalating violence: “It was YOU who taught us that peaceful protest doesn’t work.”

While there has been a lull in activity on that front in recent weeks – partly as the pro-democracy camp is looking to gain new ground via elections and burgeoning trade unionism – the problems have not gone away.

They are still demanding the introduction of universal suffrage; the unconditional pardoning of the 8,000 protesters arrested; and an independent investigation into police brutality. The authorities are not budging, so Wong predicts “the anger against the government is only going to grow and grow”.

Distinct identity Hong Kong, Wong believes, is like a foster child who was raised by a white family and, without his consent, returned to his Chinese biological parents. Mother and son have very little in common, from language and customs to the way they view their government. The more the child is forced to show affection and gratitude toward his long-lost mother, the more he resists.

His generation argues that Hong Kong isn’t British and doesn’t want to be Chinese, and its need to assert a distinct identity is growing rapidly.

In the book’s foreword, Hong Kong’s last governor Chris Patten writes that all of China’s efforts to throttle Hong Kong’s promised autonomy and increase the patriotism of a whole generation have totally backfired. “What all that has done is not to make people feel less Chinese, but more proud of being Hong Kong Chinese,” he said. “It’s odd that the Chinese Communist Party has achieved something which the British colonial government never managed.”

Successive political showdowns bear out the notion that Hong Kong has not and will never shed its colony status, Wong says. “We’ve simply been handed from one imperialist master to another.”

Police fire water cannons at pro-democracy protesters outside the government headquarters in Hong Kong on September 15th, 2019. Photograph: Isaac Lawrence/AFP/Getty Images To the Communist leadership, the financial hub is no longer the proverbial goose that lays the golden egg, he believes. And the only way to rein in what the Beijing leadership regards as “a bunch of Westernised cry-babies” is to keep them in a state of perpetual adolescence, never allowing them to achieve political maturity.

Meanwhile, China is contributing to a troubling global trend where autocratic regimes are encroaching on democratic rights both domestically and internationally, he says. “Their motivation is singular: self-perpetuation,” he says. To consolidate and maintain power domestically these regimes have shown no compunction about crushing dissenters, crippling civil society and removing other obstacles that stand in their way.

The “one country, two systems” formula for Hong Kong is also how the Communist leadership views its relationship with the rest of the world, Wong argues. Globally, China is advancing a “one world, two empires” framework in which the United States and its allies defend their liberal, rights-based ideology, while China and other one-party states demand non-interference from the free world and quietly pursue an oppressive and expansionary agenda.

Vague hope Wong will celebrate his 50th birthday in 2047, the year the “one country, two systems” framework comes to an end – the agreement that affords the city some freedoms not enjoyed on the mainland. There is no agreement or understanding in place as yet for what happens post-2047. In the run-up to 1997, a vague British hope often expressed was that China would be a much more liberal place by the time the 50 years had elapsed.

“The assumption that half a century is plenty of time for Communist China to democratise, or at least meet us halfway in terms of political reform, has been spectacularly disproved,” Wong says.

Today’s Hong Kong is the rest of the world’s tomorrow.”

Come 2047, it is possible Beijing will opt to extend the “two systems” framework, he says, or “more likely, fully integrate Hong Kong with the rest of China in a ‘one country, one system’ scenario”.

Other outside possibilities are that Hong Kongers will achieve total independence, or outlive the Communist regime as Eastern Europe did with the Soviet Union, but “both appear implausible given China’s seemingly unstoppable rise to economic and political dominance”.

Wong argues that nowhere else in the world is the struggle between free will and authoritarianism more clearly demonstrated than in Hong Kong. In the new trans-Pacific cold war, Hong Kong is the first line of defence to stop or at least slow down the dangerous rise of a totalitarian superpower, he says.

As much as Hong Kong needs the international community, the international community needs Hong Kong: “Because today’s Hong Kong is the rest of the world’s tomorrow.”

A big fan of the Avengers movie series, he says that Hong Kong’s fight against the Chinese Communist Party is an “infinity war”. He warns the rest of the world to pay close heed to what is happening in east Asia, as the infinity war that has ravaged Hong Kong for years “may soon be coming to a political theatre near you”.