WHEN Chinese President Xi Jinping came to Hong Kong a year ago to mark the 20th anniversary of the establishment of the Hong Kong Special Administrative Region (HKSAR) and to officiate at the inaugural ceremony of the new government with Carrie Lam Cheng Yuet-ngor as the Chief Executive, he gave a major speech in which he laid down the law for Hong Kong.

"Any attempt to endanger China's sovereignty and security, challenge the power of the central government and the authority of the Basic Law of the HKSAR or use Hong Kong to carry out infiltration and sabotage activities against the mainland is an act that crosses the red line, and is absolutely impermissible," he said.

Beijing was clearly unhappy with Hong Kong, what with an incipient independence movement, a combative outgoing chief executive, a deadlocked legislature and activists advocating localism or urging the end of communist-party rule in China.