The Basic Law guarantees Hong Kong “a high degree of autonomy”, but foreign affairs and defence fall under the control of the central government. To that, we may now add national security. That is presumably what Beijing means when it says “one country, two systems” is still intact and will last indefinitely, but needs to be updated from time to time. While the city’s judicial system is still independent and based on common law principles, in cases that fall under the purview of national security, those principles need not apply. When the three levels of the High Court up to the Court of Final Appeal ruled that former media tycoon Jimmy Lai Chee-ying could hire King’s Counsel Timothy Owen as his defence, the judges have grounded their rulings in the Basic Law and common law principles. But so far as the Hong Kong and central governments are concerned, national security overrides common law. That’s why the Department of Justice is seeking an interpretation with the National People’s Congress (NPC) Standing Committee. President Xi Jinping’s work report from the Chinese Communist Party’s 20th congress reaffirmed one country, two system as “the best system safeguarding the stability and prosperity of Hong Kong and Macau”, said Shen Chunyao, chairman of the NPC Standing Committee’s legislative affairs commission, at the weekend. But he added there would be occasional “improvements” to the city’s governing system. Speaking at the same seminar, deputy director of the Hong Kong liaison office Chen Dong reaffirmed the validity and importance of common law for Hong Kong. That is, presumably so long as it’s unrelated to national security. Beijing has consistently stressed that “one country” must take precedence over “two systems”. Even though common law falls under “two systems”, national security is the guarantee and protection of “one country”. Lai is facing charges under the national security law. In a nutshell, under the law, foreign lawyers have no place in national security cases, which concern solely the country’s security interests. Naturally, there has been an uproar in Western countries about Lai’s case. They see it solely as a case of press freedom and freedom of expression, or rather their suppression. At least that’s the more charitable interpretation. In his case, though, Lai is facing charges of collusion with foreign forces. They go well beyond mere criticism of government actions and policies. Such charges may include incitement and calling for sanctions and boycotts against one’s own government thatactively harm the national interest, and/or providing funding for local anti-government groups and receiving funding from foreign governments and their affiliated bodies. There is at least a prima facie argument that Lai’s case goes significantly beyond press freedom and freedom of expression. Be that as it may, the Hong Kong government’s handling of Lai’s case in particular and national security legislation in general leave much to be desired. The department last year tried to hire King’s Counsel David Perry to prosecute Lai and eight other opposition figures in a different case. To be sure, those charges involved organising and taking part in unauthorised assemblies during a 2019 protest and were unrelated to national security per se. And in the end, Perry declined to take up the case under intense public pressure from senior government officials and legal bodies in Britain. But the department’s action nevertheless muddied the water and gave the appearance that it could hire foreign lawyers but not the accused. The SAR government shelved national security legislation under Article 23 of the Basic Law 19 years ago. In the end, the NPC Standing Committee had to pass its own national security law in 2020 and listed it under Annex III of the Basic Law, thus bypassing Hong Kong approval. (Annex III lists national laws that are applicable in Hong Kong.) Had the city performed its constitutional duty, it could have had both the law and legal experience to handle such cases as Lai’s without mainland involvement such as seeking an NPC Standing Committee interpretation now.