China's National People's Congress (NPC) has approved a decision on national security legislation for the Hong Kong Special Administrative Region (HKSAR) on May 28. 

The chairman of the NPC Standing Committee said it was an important action in implementing the "One Country, Two Systems" principle. 

However, there are global concerns that this national security law once imposed will curb the freedoms enjoyed in Hong Kong. 

Is there basis for these concerns? Will the legislation risk the rights and interests of local residents and foreign investors? 

Martin Jacques, a scholar and columnist in London, said it is necessary to deal with the present chaos in Hong Kong.