China did not need to act so harshly. Hong Kong did have a serious law and order problem but posed no threat to the nation’s security despite claims to the contrary. In any case, the crackdown reflects Xi’s determination to squelch any deviation from his “China dream” of what modern China should be. One obvious byproduct: gone forever are Beijing’s fading hopes that Taiwan might someday join the mainland under some form of “one country, two systems”—one reason former leader Deng Xiaoping invented it decades ago.

The most recent opinion poll shows a 60 percent disapproval of this harsh law but the administration is undeterred. Carrie Lam plans to spend the next year or two “rectifying mistakes”—such as teaching students and their parents to think better of the Chinese regime and ruling party under a new “patriotic” education plan, perhaps replicating a mainland program of the early 1990s.

All this leaves Hong Kong changed permanently. Life there probably will remain less restrictive than elsewhere in China for some time but with freedoms steadily eroded. As the legal system withers, foreign companies will find it less attractive as a base for Chinese or regional operations. Yet Hong Kong will remain useful for prosperous mainlanders, despite its diminished role in the national economy. It’s the favorite place for Chinese companies to place new share issues, while many rich mainlanders park their vast wealth—obtained legally or otherwise—in local real estate or shell companies that route their cash abroad. However, many of Hong Kong’s best and brightest plan to emigrate; Britain has said it would welcome up to three million of them if Beijing will let them go. But a dozen protesters who tried to flee to Taiwan by speedboat were seized by the Chinese coast guard before they got far. They now face prosecution.

Much has been lost and will never return. The diverse city that made its residents proudly label themselves as Hong Kongers and which also attracted so many foreigners has been changed enormously, with the worst yet to come.

Robert Keatley is a former editor of the Asian Wall Street Journal and the South China Morning Post, both of Hong Kong.

Image: Reuters.