Over the summer, Chinese leaders reneged on an agreement with Hong Kong known as the “One Country Two Systems” principle. It’s outlined in the Sino-British Joint Declaration of 1984 and the Basic Law, Hong Kong’s constitution. Predictably, that led to popular unrest in Hong Kong, which came to a head over the weekend as police in riot gear used tear gas and batons to disperse peaceful protesters. As The Wall Street Journal editorialized, “The confrontation marks a turning point in the city’s quest for democracy. For years the people of Hong Kong avoided direct conflict with Beijing in the hope that Chinese authorities might be persuaded to grant them self-government. Now they realize that their only chance for democracy is to demand it.” Naturally, protests in China evoke memories of Tiananmen Square in 1989. We should all hope this isn’t a repeat.