This decades-old policy is linked to the ongoing protests in Hong Kong.

Protests in Hong Kong, now in its 13th consecutive week, have brought a decades-old policy of the People’s Republic of China back into focus — One Country Two Systems.

The protesters, who started occupying the city’s streets in April after the local government proposed a controversial extradition law, say Beijing is trying to violate this policy by infringing on Hong Kong’s autonomy. They want China to end its interference, while Beijing has likened the protesters to terrorists and have said that it won’t tolerate any challenge to its sovereignty over Hong Kong.

So, what’s this One Country Two Systems approach?

Origin of policy

To put it simply, it means that the Hong Kong and Macau Special Administrative Regions, both former colonies, can have different economic and political systems from that of mainland China, while being part of the People’s Republic of China.

The One Country Two Systems policy was originally proposed by Deng Xiaoping shortly after he took the reins of the country in the late 1970s. Deng’s plan was to unify China and Taiwan under the One Country Two Systems policy. He promised high autonomy to Taiwan. China’s nationalist government, which was defeated in a civil war by the communists in 1949, had been exiled to Taiwan. Under Deng’s plan, the island could follow its capitalist economic system, run a separate administration and keep its own army but under Chinese sovereignty. Taiwan, however, rejected the Communist Party’s offer.

The island has since been run as a separate entity from the mainland China, though Beijing never gave up its claim over Taiwan.

Return of colonial territories

The idea of two systems in one country resurfaced when Beijing started talks with Britain and Portugal, who were running Hong Kong and Macau, respectively.

The British had taken control of Hong Kong in 1842 after the First Opium War. In 1898, the British government and the Qing dynasty of China signed the Second Convention of Peking, which allowed the British to take control of the islands surrounding Hong Kong, known as New Territories, on lease for 99 years. London promised Peking that the islands would be retuned to China after the expiry of the lease, in 1997. Macau, on the other side, had been ruled by the Portuguese from 1557. They started withdrawing troops in the mid-1970s.

In the 1980s, Deng’s China initiated talks with both Britain and Portugal for the transfer of the two territories. In talks, Beijing promised to respect the region's autonomy under the One Country Two Systems proposal. On December 19, 1984, China and the U.K. signed the Sino-British Joint Declaration in Beijing, which set the terms for the autonomy and the legal, economic and governmental systems for Hong Kong post 1997.

Similarly, on March 26, 1987, China and Portugal signed the Joint Declaration on the Question of Macau in which China made similar promises for the region of Macau after it was handed over to Beijing.

Hong Kong returned to Chinese control on July 1, 1997, and Macau’s sovereignty was transferred on December 20, 1999. Both regions became Special Administrative Regions of China. The regions would have their own currencies, economic and legal systems, but defence and diplomacy would be decided by Beijing. Their mini-Constitutions would remain valid for 50 years — till 2047 for Hong Kong and 2049 for Macau. It is unclear what will happen after this term.

What triggered the current crisis?

In recent years, there has been a growing outcry from Hong Kong’s pro-democracy civil society against China’s alleged attempts to erode the city’s autonomy. This has created tensions between the city’s youth and the local government, which is effectively chosen by Beijing.

In 2016-17, six legislators critical of Beijing were debarred. In 2018, the Hong Kong National Party, a localist party that has been critical of Beijing, was outlawed. This year, Carrie Lam, the Chief Executive of Hong Kong, proposed the extradition Bill, which sought to extradite Hong Kongers to places with which the city doesn’t have extradition agreements. Critics said it would allow the city government to extradite Beijing critics to mainland China where the judicial system is subservient to the ruling Communist Party.

This triggered the protests, and they went on despite Ms. Lam’s decision to suspend the Bill. The protesters, who often clashed with the police, now want the Bill to be formally withdrawn, Ms. Lam to resign, the arrested protesters to be released and the city’s electoral system to be reformed.