A major turning point in U.S.-Chinese relations occurred Thursday. It nominally involves the future of Hong Kong, but has major significance for Washington and the wider world.

China’s National People’s Congress approved a security law that will allow Beijing’s security agencies to crack down directly on the civil liberties of Hong Kong residents, who have been protesting the regime’s indirect efforts to shrink their freedoms since last summer.

China promised Hong Kong a full range of political freedoms such as freedom of speech and press and an independent judiciary after it regained control of the territory from Great Britain in 1997. Hong Kong autonomy, under the “one country, two systems” framework, was endorsed by U.S. legislation in 1992.

However, Chinese leader Xi Jinping has been eager in recent years to exert tighter Chinese control over the territory and apparently believes he can do so now with minimal cost. Buoyed by Beijing’s success (after a rocky start) in crushing COVID-19, in contrast to the chaotic U.S. response, he clearly thinks the world will abandon Hong Kong.

That would be a dangerous mistake, because Hong Kong has become the symbol of Xi’s aggressive global approach.

“Hong Kong is a test of whether people [around the world] kowtow to China, whether they say no to pressure from China to implement its authoritarian ideology,” I was told by phone by Joshua Wong, the 24-year-old organizer of the 2014 Umbrella Movement that peacefully shut down the territory to protest earlier efforts to curb its freedoms.

I met with Wong during a November visit to Hong Kong when the city’s streets were crammed with demonstrators of all ages and professions. They were protesting the Beijing-backed Hong Kong government’s effort to pass a law allowing residents to be extradited for trial on the Chinese mainland, where the courts are controlled by the Communist Party. Sixteen-year-old high school protesters on the streets spoke to me passionately, as did Wong, about the need to protect rule of law in the territory.

Now, says Wong, the new Chinese law will enable Beijing to openly deploy its secret police and security forces in Hong Kong and shut down civic and human rights defenders the way they do on the mainland. “The new law serves as a weapon to rip out all democratic aspirations in Hong Kong,” he told me. “There is no transparency on how it will be implemented.”

What makes China’s move on Hong Kong even more disturbing, beyond the pull of democratic Davids fighting Goliath in Beijing, is that Beijing’s move reflects the expanding ambitions of Xi Jinping.

The Chinese leader has no doubt been emboldened by the political divisions in the West, including the rise of populism, and the weakening of Western alliances under President Donald Trump. And while COVID-19 has wounded China economically, the country is emerging from virus shutdown far sooner than the United States and Europe. So this is an opportune moment for Xi to take action against Hong Kong.

If the new Chinese security law meets no resistance, Chinese leaders could take this as an indication that they can continue to militarize the South China Sea, gnaw at neighbors’ borders, and squeeze Taiwan. “If Hong Kong falls, it affects the interests of the Western world,” Wong told me. “Next is Taiwan [which has close military ties with the United States].” He wants “world leaders to send a warning signal to China, not just talk.”

What kind of warning signal will register with Beijing is the burning question. In November, Congress passed the Hong Kong Human Rights and Democracy Act with a veto-proof bipartisan majority, forcing a reluctant President Trump to sign it. The act authorizes the administration to revoke the special trade status the United States grants Hong Kong -- if the State Department rules that China has taken away Hong Kong’s autonomy.

Secretary of State Mike Pompeo made that determination Wednesday. And Friday, President Trump announced the U.S. would end almost all aspects of Hong Kong’s special status.

Yet eliminating that special trade status will also gravely hurt the citizens of Hong Kong. And doing it immediately, and totally, is likely to undercut any slim chance of persuading Beijing to soften its stance towards Hong Kong. Especially if the United States acts on its own.

Wong and other Hong Kong activists say the special status should be removed in stages, sending Beijing a clear warning. Although Hong Kong is no longer as economically important to mainland China as it once was, the territory is still the gateway for Western investors who want to access the mainland Chinese market, and accounts for nearly three-quarters of initial public offerings for Chinese firms, according to Hong Kong Watch.

Most important, for U.S. pressure to make an impact it must be done in concert with allies, not as part of Trump’s blame-China bluster aimed to distract from COVID-19. Otherwise, say China experts, it will not budge Beijing.

Together with European and Asian allies, the Trump administration “should collectively set a legislative red line and make a quiet demarche to Beijing: Continue down this path and the world’s most important economic powers will revoke the territory’s special economic status,” writes the Cato Institute’s Doug Bandow.

In other words, to stand with Hong Kong, Trump must stand together with allies he’s dissed and stand up to Xi, whom he regularly praises.

Stand with Hong Kong, stand firm, and stand with the democratic world.