Pro-Beijing lawmakers fast-tracked the legislation, with tough punishment for acts considered "external interference," insurrection and other offenses.
Two teenagers bonded over high school Model United Nations. A decade later, one is in self-exile. The other waits for her and their other friends to return to the Hong Kong they once knew.
Apple Daily was closed, universities were muzzled and prominent activists were either jailed or exiled. The national security law has surely made an impact in Hong Kong in its first year in force.
Hong Kong is supposed to be a semiautonomous enclave of China, "one country, two systems." But China is moving to impose a sweeping national security law on the city, which critics say is illegal.
Protesters rained down bricks and Molotov cocktails on government buildings and riot police deployed tear gas in some of the most forceful police responses since protests began in early June.
The Hong Kong protesters are appealing to U.S. authorities and to international travelers as they press their government to keep its distance from Beijing.