As China’s communist leaders prepare to impose a draconian new national security law on supposedly autonomous Hong Kong, officials in Beijing and locally are trying to assure the city’s anxious and angry residents that nothing much will change.

The legislation, approved by the National People’s Congress (NPC) on Thursday, will only apply to a tiny number of ‘terrorists’ and their foreign backers, they say. Local police and courts will still be in charge. The new restrictions, they say, will actually make Hong Kong safer and more stable for overseas investors. And besides, every Western country has its own version of a national security law, so criticism from foreign capitals amounts to hypocrisy and fearmongering.

But Hong Kong’s elected pro-democracy politicians, academics, lawyers, journalists and overseas business groups believe precisely the opposite is true. Everything will change.

After steady erosion, they say—the kidnapping of five Hong Kong booksellers, the expulsion of a Financial Times journalist, China weighing into local court decisions—the law will mark the death of Hong Kong’s autonomy, and of the unlikely dream of ‘one country, two systems’.

The remaining question for many now is how long this freewheeling, capitalist enclave can thrive as a global financial centre and multinational business hub once it becomes just another Chinese city, subject to the controls used to stifle dissent on the mainland.

While Hong Kong’s political future is being dictated from Beijing, its economic future might be decided in Washington.

Hong Kong’s international standing could be further eroded now that the United States poised to implement new sanctions. Secretary of State Mike Pompeo has indicated that the White House could revoke its special trade status. President Donald Trump could then impose on Hong Kong punitive tariffs on exports and controls on sensitive technology as he has on China.

One prominent American businessman in Hong Kong predicted that trade, technology and the overall business climate could diminish rapidly. He said the financial sector could be less immediately affected given the strength of the Hong Kong stock exchange, the world’s third largest behind New York and London with over 2,000 listed companies. But that could change, too, if overseas talent becomes harder to attract, if faith in the legal system wanes and if the market manipulation common on the mainland takes hold here.

Hong Kong is already less vital to China than it was 23 years ago at the time of the handover, when its economy accounted for nearly 16% of mainland China’s GDP. Now its barely 3% and ships bypass Hong Kong for mainland ports in Shenzhen and Shanghai.

But the city remains important. Most of China’s foreign direct investment comes through Hong Kong, contracts are signed there because of its reliable legal system, information—vital to capital movements—still flows freely, and Hong Kong’s dollar is a convertible currency pegged to the US dollar. All of that could now be in danger. An immediate rush to the exits is unlikely, but Singapore is likely to be perceived as a safer and more stable long-term bet.

There are too many unknowns to be certain of any outcome. The new law is still being written in Beijing, and will not likely be implemented here for several months. And Pompeo’s statement decertifying Hong Kong only begins a process, leaving Trump with many options depending on how hard he wants to try to punish Beijing.

Jittery residents are waiting to see the fine print of the law that, as expected, won overwhelming support from the NPC, China’s rubber-stamp parliament, with 2,878 votes and only one against, with six abstentions. Now it goes to the more powerful NPC Standing Committee, charged with crafting the precise wording. That will take several weeks.

Will people arrested in Hong Kong for violating the law be tried in local courts, where defendants enjoy more rights, including under international human rights covenants? Or could they be shipped to mainland courts where prosecutors have a 99% conviction rate? Will the law be enforced primarily by the local police, or by agents of China’s feared Public Security Bureau?

And will it be retroactive so that someone can be prosecuted for a statement or a tweet made last year before it was in force? That has many trying to scrub their social media accounts, and downloading virtual private networks, which are illegal in China, though commonly used to bypass censors.

The only template suggesting how the law might be implemented in Hong Kong is the way it’s used in mainland China. That paints a terrifying picture.

Journalists, scholars, lawyers, human rights activists and workers with non-government organisations have all been detained under the mainland’s national security law, usually charged with the catch-all crime of ‘subverting state power’ or ‘inciting to subvert the state’. Trials are typically closed if they involve ‘national security’. Many documents, from mundane economic statistics to the number of people executed for capital crimes, are classified as ‘state secrets’ and reporting them, or possessing them, can lead to prison. Criticism of the one-party state or calls for multiparty democracy amount to crimes of incitement.

Backers of the law say it will only be applied to crimes like treason, subversion, foreign interference and secession, but there are unlikely to be clear legal signposts to what those vague terms mean.

Can Hong Kong academics researching mainland trends run afoul of the law? Can a university hold a symposium on Tibet or Taiwan and invite all sides to participate? Could publishing an interview with the Dalai Lama, or Taiwanese President Tsai Ing-wen, be deemed a crime? And how broadly will the new law define ‘foreign interference’, which could mean the normal activities of American or Australian NGOs, like human rights or labour groups, providing funding or training for local partners?

In China, attacks on the communist party and its symbols are not tolerated. But in Hong Kong, slogans and banners mocking the party, the Chinese flag and Xi Jinping are common. Will they be outlawed? Already, the local legislature, controlled by pro-Beijing forces, is trying to ram through an unpopular bill to make it a crime to disrespect the Chinese national anthem, ‘March of the Volunteers’.

Local pro-China figures have already hinted that the annual vigil commemorating the 1989 Tiananmen Square massacre of hundreds of pro-democracy students could be outlawed.

Little is known about Washington’s next steps.

Despite its divided and divisive politics, there’s a strong and unusually bipartisan consensus in the US to hold China to account for its human rights abuses and for rolling back Hong Kong’s freedoms. Congress has sent to the White House a bill to sanction Chinese officials for their brutal suppression in Xinjiang, where more than a million ethnic Muslim Uyghurs have been sent to concentration camps for ‘re-education’.

Trump has been agitating to punish China for its early lack of transparency over the initial outbreak of the deadly coronavirus in Wuhan, most likely at a wildlife and seafood market not far from a secretive virology laboratory. But Hong Kong’s economic fate could also be tied to the US–China trade war. If Hong Kong loses its special trading status and becomes subject to punitive tariffs, the economic blow to a city reeling from months of protests and the pandemic could be devastating.

The anti-subversion law, and the crackdown it presages, is the result of a collision between Hongkongers’ aspirations for genuine autonomy and the Chinese Communist Party’s imperative to impose control over a restive former British colony that never fully accepted being incorporated into the mainland.

After months of protests, many Hong Kong activists and outside observers were hoping, optimistically, that China’s rulers would not risk tarnishing this city’s global brand as a financial centre, or the approbation from the wider world, with a complete crackdown, and that some compromise might be reached. But it now appears that for China’s leadership, it’s most important to control Hong Kong through force and to crush dissent that might spill over the border.

Before 1997, when Britain handed over the colony, Hong Kong’s fate was decided in London and Beijing, with its people having no say.

History appears to be repeating itself. Hong Kong’s future is now being shaped in Beijing and Washington. And once again, Hongkongers are on the outside looking in.