The Law of the People's Republic of China on Safeguarding National Security in the Hong Kong Special Administrative Region was passed unanimously at the 20th session of the Standing Committee of the 13th National People's Congress, China's top legislature, on June 30. This prompted some Western countries to allege the promulgation of the national security law in the SAR "lies in direct conflict with its international obligations under the principles of the legally-binding, UN-registered Sino-British Joint Declaration".
But the allegation doesn't hold water on five counts.
The issue should be analyzed in terms of the Vienna Convention on the Law of Treaties, which was concluded in 1969 and came into force in 1980, and the United Kingdom and China both are state parties to it. The VCLT is reflective of customary international law, which governs the treaty relations between and among non-state parties. This is important because China did not accede to the VCLT until Sept 3, 1997. In other words, China was not a state party to the VCLT when the Sino-British Joint Declaration was concluded in 1984.
Joint Declaration should be interpreted in good faith
According to Article 2 of the VCLT, "treaty means an international agreement concluded between States in written form and governed by international law, whether embodied in a single instrument or in two or more related instruments and whatever its particular designation". As such, the Sino-British Joint Declaration meets the definition of "treaty", its formal title notwithstanding.
First, the Sino-British Joint Declaration was concluded between China and the UK, both sovereign states, and the text of the instrument itself indicates it is an agreement between China and the UK. The Joint Declaration consists of eight paragraphs and three annexes, with each part having the same status. In particular, Paragraph 8 avers that "this Joint Declaration and its Annexes shall be equally binding". Also, the Joint Declaration is "governed by international law", as it stipulates the sovereign and administrative arrangement of Hong Kong during the transitional period. Hence, it is safe to conclude that the Sino-British Joint Declaration is a bilateral treaty between China and the UK.
The Chinese government has acknowledged the legal status of the Joint Declaration as a legally binding treaty. And the instrument, including the Sino-British Joint Declaration per se and three annexes, was registered as a treaty at the United Nations by the Chinese and British governments on June 12, 1985.
Since the Joint Declaration is a bilateral treaty, the rights and duties of the parties to it should be examined according to the provisions of the VCLT, especially those relating to treaty interpretation. Article 31 of the VCLT says a treaty must be interpreted in good faith and in the light of its object and purpose, and Article 26 enshrines the principle of pacta sunt servanda (agreements are binding and should be implemented in good faith).
The purpose of the Joint Declaration is reflected in its preamble: to reach a "proper negotiated settlement of the question of Hong Kong, which is left over from the past". The UK acquired Hong Kong Island in 1842 and the Kowloon Peninsula in 1860, and leased the New Territories in 1898 for 99 years by unequal treaties with the Qing Dynasty (1644-1911) when China was weak. Therefore, the overarching purpose of the Joint Declaration is to ensure a smooth transfer of sovereignty of Hong Kong, Kowloon and the New Territories from the UK to China in 1997, and correct the historical injustice; and this is vital to understanding the rights and duties of the parties to the treaty.
Key provisions of treaty need in-depth study
Paragraph 1 of the Joint Declaration is a unilateral statement of the Chinese government, which says China would resume the exercise of its sovereignty over the Hong Kong area (including Hong Kong Island, Kowloon and the New Territories, hereinafter referred to as Hong Kong) from July 1, 1997, which incorporates the principal right of the Chinese government under the instrument. And Paragraph 2 is a unilateral statement of the British Government, which says the UK would hand over Hong Kong to China on July 1, 1997, which, correspondingly, reflects the principal duty of the British government hereunder. The two paragraphs are complementary, and together constitute the key provisions of the instrument.
Paragraph 3 is a unilateral statement of the Chinese government, which sets forth the basic policies of China regarding Hong Kong in 12 subparagraphs. The policies set out in this paragraph are elaborated in Annex I. Paragraphs 4 to 6 and Annexes II and III stipulate arrangements during the transitional period. And Paragraphs 7 and 8 are about the Joint Declaration's implementation and entry into force.
However, Paragraph 3 is unique in terms of its content and nature. It is different from Paragraphs 1 and 2 because it is "self-governing" and its performance is not dependent on any other paragraph. To be more specific, though Paragraphs 1, 2 and 3 are unilateral statements of one party, Paragraphs 1 and 2 are dependent on each other, as they each cannot be fulfilled without the simultaneous performance of the other. But Paragraph 3 is distinct, as the Chinese government can fulfill it unilaterally and independently without the British government playing any role at all.
Also, Paragraph 3 is different from Paragraphs 4 to 8, since the latter reflect the common agreements of both parties, rather than being unilateral statements by one party alone. So the following conclusions can be drawn:
・ After the smooth transfer of sovereignty of Hong Kong, Kowloon and the New Territories from the UK to China on July 1, 1997, Paragraphs 1 and 2 had been fulfilled;
・ After the NPC promulgated the Basic Law of the SAR, which incorporates the basic policies of China regarding Hong Kong, China had fulfilled its duties under Paragraph 3 and Annex I;
・ By maintaining the economic prosperity and social stability of Hong Kong during the transitional period, both parties fulfilled their duties under Paragraph 4;
・ After the Sino-British Joint Liaison Group, set up to ensure smooth transition post-handover, was disbanded in 2000, both parties had completed their duties in line with Paragraph 5 and Annex II;
・ After the Land Commission, established immediately after the Joint Declaration came into force, was dissolved on June 30, 1997, the conditions of Paragraph 6 and Annex III had been fulfilled;
・ And after the Sino-British Joint Declaration was signed by the Chinese premier and British prime minister on behalf of their respective governments, came into force with the exchange of instruments of ratification on May 27, 1985, and registered by the Chinese and British governments at the UN on June 12, 1985, the two sides had fulfilled their duties pertaining to Paragraphs 7 and 8.
UK, other states not entitled to supervise HK affairs
Since the Joint Declaration is a bilateral treaty between China and the UK, after all its requirements were fulfilled, the UK has no sovereignty, jurisdiction or "right of supervision" over Hong Kong. This is not to deny the UK's entitlement to require China to respect the Joint Declaration. As the parties to the instrument, both China and Britain have the right to ask each other to honor it. But Britain's right to ask China to respect the Joint Declaration is not absolute; instead, it is subject to the limitation of international law.
To begin with, when requiring China to respect the Joint Declaration, the UK should also abide by pacta sunt servanda. In other words, the UK should exercise such right based on good faith, not on arbitrary interpretation of the Joint Declaration. So the UK's allegation that China's decision to promulgate the national security law in the SAR conflicts with China's international obligations under the Joint Declaration is baseless.
In fact, given that the "one country, two systems" principle is enshrined in the Basic Law of the SAR and the Chinese central government has reiterated that it respects the principle, and it will not be changed or undermined by the national security legislation, anybody with just basic knowledge of international law would conclude that the allegations are not based on facts.
Also, the UK should not violate the principle of non-interference in another country's internal affairs when it requires China to respect the Joint Declaration. The principle of non-interference in another country's internal affairs is part of international law, and enshrined in the UN Charter (Article 2.4). The International Court of Justice was unambiguous when it ruled on the Nicaragua case that" (T) he principle of non-intervention involves the right of every sovereign State to conduct its affairs without outside interference; though examples of trespass against this principle are not infrequent, the Court considers that it is part and parcel of customary international law... (and) international law requires political integrity... to be respected". (ICJ Reports 1986, p.106, para. 202)
One state cannot interfere in another state's internal affairs
It went on to say that "the principle forbids all States or groups of States to intervene directly or indirectly in the internal or external affairs of other States" and that "a prohibited intervention must accordingly be one bearing on matters in which each State is permitted, by the principle of State sovereignty, to decide freely. One of these is the choice of a political, economic, social and cultural system, and the formulation of foreign policy."
Therefore, under no circumstances should the UK impose its unilateral interpretation of the Sino-British Joint Declaration on China, and vice versa. On issues that fall within the domestic affairs of China, the UK has no right to interfere, directly or indirectly. And since national security in essence is part of a sovereign country's domestic affairs, the UK has no right to meddle in China's decision to promulgate the national security law in Hong Kong.
Apart from the UK, some other Western countries, the United States in particular, have also been interfering in Hong Kong affairs. In 1992, the US passed the Hong Kong Policy Act, which was amended by the so-called Hong Kong Human Rights and Democracy Act of 2019. Under the framework of these acts, the US State Department is required to submit an annual report on recent developments in Hong Kong to the Congress, allegedly to "support the high degree of autonomy and fundamental rights and freedoms of the people of Hong Kong, as enumerated by the Joint Declaration".
The situation in Hong Kong has also been an important part of the annual reports of the US Congressional Executive Commission on China and the US-China Economic and Security Review Commission. The maxim pacta tertiis nec nocent nec prosunt (a treaty binds the parties and only the parties, it does not create obligations for a third state) is the fundamental principle of a treaty. Yet the US has been monitoring the implementation of the Joint Declaration despite not being a party to the treaty and therefore having no right to supervise the implementation of the Joint Declaration.
As the prohibition of intervention "is a corollary of every state's right to sovereignty, territorial integrity and political independence", according to L.F.L. Oppenheim who is considered the "father of international law" by many, the US is not allowed by international law to interfere in Hong Kong affairs. Consequently, the US is not entitled to interfere in China's decision to promulgate the national security law in Hong Kong on the grounds of the Joint Declaration or any other international treaties.
China's Constitution is the legal basis for HK Basic Law
Some Western countries argue that the Basic Law of the SAR is a product of the Joint Declaration. However, such argument is baseless, because the Constitution of the People's Republic of China is the legal basis for the Basic Law of the SAR.
First of all, China's Constitution makes it clear that it is the legal basis for the establishment of special administrative regions and the formulation of the Basic Law of the SAR. The current Constitution of China was enacted by the NPC in 1982, two years before the conclusion of the Sino-British Joint Declaration.
The preamble to the 1982 Constitution states "it is the fundamental law of the state and has supreme legal authority". Especially, Article 31 of the Constitution states: " (T) he state may establish special administrative regions when necessary. The systems to be instituted in special administrative regions shall be prescribed by law enacted by the National People's Congress in the light of specific conditions". As such, China's Constitution is the legal basis for the establishment of special administrative regions and the formulation of the Basic Law of the Hong Kong SAR as well as the Macao SAR.
Second, the Joint Declaration itself proclaims that China's Constitution is the legal basis for the Basic Law of Hong Kong. As mentioned before, Paragraph 3 of the Joint Declaration is a unilateral statement of the Chinese government which sets forth the basic policies of China regarding Hong Kong.
The central government has elaborated those basic policies in Annex I thus:" (T) he Constitution of the People's Republic of China stipulates in Article 31 that 'the state may establish special administrative regions when necessary. The systems to be instituted in special administrative regions shall be prescribed by laws enacted by the National People's Congress in light of the specific conditions.'... The National People's Congress of the People's Republic of China shall enact and promulgate a Basic Law of the Hong Kong Special Administrative Region of the People's Republic of China in accordance with the Constitution of the People's Republic of China …"
This establishes without any doubt that China's Constitution, not the Sino-British Joint Declaration, is the legal basis of the Basic Law of Hong Kong.
And third, the Basic Law of Hong Kong affirms that China's Constitution is its legal basis, as the last paragraph of its preamble states: " (I) n accordance with the Constitution of the People's Republic of China, the National People's Congress hereby enacts the Basic Law of the Hong Kong Special Administrative Region of the People's Republic of China, prescribing the systems to be practiced in the Hong Kong Special Administrative Region, in order to ensure the implementation of the basic policies of the People's Republic of China regarding Hong Kong".
Therefore, the promulgation of the Basic Law of Hong Kong by the NPC reflects China's performance of its duties under the Joint Declaration. But the Joint Declaration, an international treaty, is not, and cannot be, the legal basis or source of the Basic Law of Hong Kong. China's Constitution, as the fundamental law of the State and having supreme legal authority, is the legal basis for the establishment of special administrative regions and the Basic Law of the Hong Kong.
After systematically examining the Sino-British Joint Declaration in terms of international law, one can safely conclude that the Joint Declaration is not relevant to national security legislation in Hong Kong. As long as the law is enacted and promulgated pursuant to China's Constitution and the Basic Law of Hong Kong, its legitimacy cannot be challenged. And foreign countries, including the UK and the US, have no right to question China's decision to promulgate the national security law in Hong Kong on grounds of the Joint Declaration or any other international treaty.