National security is a matter of national interest and the central government establishing a security agency in the Hong Kong Special Administrative Region is natural and rational, experts said.

The Standing Committee of the National People's Congress, China's top legislature, unanimously passed on Tuesday the National Security Law for Hong Kong, which came into force on Tuesday night.

Tian Feilong, an associate professor at Beihang University's Law School in Beijing, said it would go beyond the HKSAR organs' control if the cases involved external forces, cross-border intelligence collection or some extremist activities

The law authorizes the central government to set up a national security office in Hong Kong to investigate special criminal cases, collect intelligence and support the SAR government in performing its duties in safeguarding national security.

The SAR government is given primary responsibility in handling national security affairs and jurisdiction－including criminal investigation, prosecution and trial. But in four categories of crimes, which are secession, subversion, terrorism and collusion with foreign or external forces, the law also allows the national office to exercise jurisdiction over a small number of criminal cases under specific circumstances.

The law clarifies that the three specific circumstances are when "the case is complex due to the involvement of a foreign country or external elements, making it difficult for the region to exercise jurisdiction over the case; a serious situation occurs where the regional government is unable to effectively enforce the law; or a major and imminent threat to national security has occurred."

The law further explains that if the criminal case fits into one of the three categories, the office should initiate an investigation and the case will be prosecuted and adjudicated by a prosecuting body and a court designated by the Supreme People's Procuratorate and the Supreme People's Court.

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Limited power

Provisions on the national security office's power have sparked some concern over whether it would impede Hong Kong's judicial autonomy, but experts said it is reasonable because the HKSAR organs may have limited power in handling certain cases.

Tian Feilong, an associate professor at Beihang University's Law School in Beijing, said it would go beyond the HKSAR organs' control if the cases involved external forces, cross-border intelligence collection or some extremist activities.

He said that given the grim security situation in Hong Kong, the four crimes listed in the law may not be effectively dealt with solely by Hong Kong authorities. Therefore, it is necessary for the central government to give guidance so that Hong Kong's legal system in safeguarding national security is more seamless, complete and systematic.

Zhang Jian, director of the Hong Kong and Macao Research Office at the Shanghai Institutes for International Studies, said the central security office maintaining jurisdiction over a very few cases is fully in line with international practice

In cases involving foreign forces, for example, meaning the case would present a foreign affairs concern, Hong Kong authorities may lack adequate jurisdictional capabilities without governance from central authorities, Tian said, adding that the central agency maintaining a certain jurisdiction is like the creation of a legal intermediary.

"This can basically tackle all the foreseeable challenges and prevent Hong Kong from entering a state of emergency that would bring an excessive impact on its prosperity and stability," he added.

Zhang Jian, director of the Hong Kong and Macao Research Office at the Shanghai Institutes for International Studies, said the central security office maintaining jurisdiction over a very few cases is fully in line with international practice.

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"Internationally, it is all sovereign states and central governments that handle national security affairs. No single country is like China, which authorizes a local government to take charge. It's all a matter of the state," he said.

According to Zhang, although the central government authorizes Hong Kong to enact its own national security law, as stipulated in Article 23 of the Basic Law, it is only a "partial authorization" as Article 14 and 18 of the Basic Law still maintain central authority in matters of military force, defense, foreign affairs, turmoil and states of emergency.

"It is the same with this new National Security Law. The HKSAR primarily enforces the law but the power of interpretation of this law is vested in the NPC Standing Committee. The central government's office may not even have to use that power, but it needs to be stated clearly in the law," he added.

Trust in Hong Kong

Wang Lei, a law professor at Peking University, said safeguarding national security falls squarely under the purview of the central authorities. Because it is the central government's responsibility, it has the power and obligation to supervise, manage and coordinate relevant work even if it does not handle criminal cases itself.

Zou Pingxue, director of Shenzhen University's Center for Basic Laws of Hong Kong and the Macao SAR, said there's no need to worry that Hong Kong's judicial autonomy or human rights will be threatened now that the new law has taken effect.

He said the law has shown great reliance on and trust in the SAR government, taken into account the characteristics of Hong Kong's common laws to the greatest extent and maximized the role of Hong Kong's local legal system and enforcement mechanism.