From this week, Hong Kongers holding British National Overseas (BNO) passports will be able to apply for a new scheme that provides a route to UK citizenship.
An exodus from Hong Kong, the astonishing hub of trade and freedom, may now be likely.
The decision to open UK arms to Hong Kongers is one of the bravest and best things that Britain has done in recent years, perhaps one of the most important that Prime Minister Boris Johnson, Foreign Secretary Dominic Raab and Home Secretary Priti Patel will collectively make - providing sanctuary, freedom and even life for people who might otherwise be accused of political crimes and disappear into China's opaque prison system.
It was not an easy decision. China may seek revenge. Its announcement on Friday that it will not recognise BNO passports is largely symbolic, but may trap some Hong Kongers, possibly permanently. It is malicious, mean-spirited and reminiscent of the USSR.
The UK's offer of asylum - and that is effectively what is on offer - is the result of the suffocation by China's Communist rulers of the "one country, two systems" policy agreed between the UK and Beijing when Britain relinquished control of Hong Kong in 1997.
For people who have never lived in a totalitarian or authoritarian state, it is difficult to understand the difference between open and closed societies. In Hong Kong, basic rights such as freedom of speech and freedom from arbitrary arrest used to be taken as a given, just as in the rest of the free world. In China, above a certain level, they are absent and China is now importing its one-party system into Hong Kong.
Millions of Hong Kongers are direct descendants of refugees who fled the worst excesses of Chairman Mao's Great Leap Forward famine and the Cultural Revolution. Many have experienced communism and understand the value of freedom.
Sovereignty of Hong Kong was passed to China on the understanding that Hong Kong's freedom would be respected. Beijing has broken promises enshrined in international law. China is a great nation but it, as well as Hong Kong, will be poorer for the decisions it has taken.
The diminishment of rights in Hong Kong affects a minority now, but in the coming years it will affect many more. Hong Kong and China's authoritarian future is not written in stone, but like in Putin's Russia, everyone may have to live with it for years, if not decades.
There will be Britons who complain about the numbers of Hong Kongers who may seek sanctuary in the country, which may run into six figures. I sympathise with this argument. I voted for Brexit in part to regain control of the country's borders. But Brexit wasn't about shutting out the world, but being able to decide who comes in.
The Hong Kongers who come to Britain will overwhelmingly do so for values, ethics and politics, not just economics. The comparison here is not to the EU and free movement, which limited dramatically the UK's ability to control its borders, but with events in 1972, when a Conservative government rightly gave asylum to Ugandan Asians as they were being expelled by Idi Amin's brutal dictatorship.
That was an example of moral generosity; doing the right thing, not just the easy thing. As Ugandan Asians have thrived in the UK, so Hong Kongers will too.
Hong Kongers are highly educated and skilled people, part of the Western world. Many are fluent in English and they instinctively share Western values. They are also part of a global diaspora linked to Asian states such as Singapore and Malaysia, as well as Canada, Australia and the US.
There will be challenges, depending on how many Hong Kongers arrive, and perhaps Covid has prevented work to develop an integration strategy to help the new arrivals into Britain.
This should be prioritised to resolve practical issues. Churches, charities, community groups and local councils will all have a role. While some Hong Kongers are wealthy, many are not. They should all be valued equally.
By welcoming Hong Kongers, the UK is respecting and living up to the values it holds itself to. It would have been easier to tut-tut, virtue signal, and then do nothing. But this decision sets a marker for Global Britain.
The UK has a noble tradition in the past half-millennium of welcoming victims of persecution, including French Huguenots, Russian Jews and Ugandan Asians. Within reason and common sense, the country should not be afraid to be a refuge for those who need one.
Thank you, Mr Johnson, Mr Raab, and Ms Patel, and welcome, Hong Kongers.
Bob Seely is vice-chairman of the All-Party Parliamentary Group on Hong Kong