China published a white paper about Hong Kong and national security a day after former media boss Jimmy Lai Chee-ying was jailed for 20 years under the city’s national security law. “The Chinese government is publishing this white paper to review Hong Kong’s endeavors in safeguarding national security and the experience and insights gained in the process, and also to clear up confusion and misunderstandings surrounding the issue to build consensus, and to ensure the high-quality development of...