One country, two systems

'One country, two systems' is a constitutional principle formulated by Deng Xiaoping, the Paramount Leader of the People's Republic of China (PRC), for the reunification of China during the early 1980s. He suggested that there would be only one China, but distinct Chinese regions such as Hong Kong and Macau could retain their own economic and administrative systems, while the rest of the PRC (or simply 'China') uses the socialism with Chinese characteristics system. Under the principle, each of the two regions could continue to have its own governmental system, legal, economic and financial affairs, including trade relations with foreign countries. Hong Kong was a colony of the United Kingdom, ruled by a governor for 156 years from 1841 (except for four years of Japanese occupation during WWII) until 1997, when it was returned to Chinese sovereignty. China had to accept some conditions, stipulated in the Sino-British Joint Declaration, such as the drafting and adoption of Hong Kong's mini-constitution before its return. The Basic Law ensured Hong Kong will retain its capitalist economic system and own currency (the Hong Kong Dollar), legal system, legislative system, and people's rights and freedom for fifty years, as a special administrative region (SAR) of China. Set to expire in 2047, the current arrangement has permitted Hong Kong to function as its own entity in many international settings (e.g., WTO and the Olympics) rather than as a part of China. The Chinese renminbi is not legal tender in Hong Kong. Likewise, the Hong Kong Dollar is not accepted in stores in China. With this arrangement, a permit or visa is required when passing between the borders of Hong Kong and China, and people in Hong Kong generally hold Hong Kong SAR passports rather than Chinese passports. The official languages are a major factor besides the history of the former colony that has made Hong Kong and China distinct from each other, as Cantonese and English are the most widely used languages in Hong Kong while Mandarin is the official language of China. The central government in Beijing maintains control over Hong Kong's foreign affairs as well as the legal interpretation of the Basic Law. The latter has led democracy advocates and some Hong Kong residents to argue that the territory has yet to achieve universal suffrage as promised by the Basic Law, leading to mass demonstrations in 2014. Deng Xiaoping proposed to apply the principle to Hong Kong in the negotiation with the British Prime Minister, Margaret Thatcher over the future of Hong Kong when the lease of the New Territories (including New Kowloon) of Hong Kong to the United Kingdom was to expire in 1997. The same principle was proposed in talks with Portugal about Macau. The principle is that, upon reunification, despite the practice of socialism in mainland China, both Hong Kong and Macau, which were colonies of the UK and Portugal respectively, can retain their established system under a high degree of autonomy for at least 50 years after reunification. What will happen after 2047 (Hong Kong) and 2049 (Macau) has never been publicly stated. Chapter 1, Article 5 of the Hong Kong Basic Law, the constitutional document of the Hong Kong Special Administrative Region, reads: The establishment of these regions, called special administrative regions (SARs), is authorised by Article 31 of the Constitution of the People's Republic of China, which states that the State may establish SARs when necessary, and that the systems to be instituted in them shall be prescribed by law enacted by the National People's Congress in light of the specific conditions. The SARs of Hong Kong and Macau were formally established on 1 July 1997 and 20 December 1999 respectively, immediately after the People's Republic of China (PRC) assumed the sovereignty over the respective regions.