During the 2017 Chinese New Year, late at night, a well-connected Chinese-born businessman named Xiao Jianhua was abducted from his apartment in the Four Seasons Hotel Hong Kong, apparently in coordination with Chinese law enforcement. The bewildered billionaire was placed in a wheelchair, covered in a blanket and rolled away. Later, he reappeared in Shanghai, where last year he was sentenced to 13 years in prison on corruption charges.  But Xiao’s plainclothes captors had been breaking the law too: The Chinese security agents were not authorized to operate in the city.  On paper, Hong Kong is a “special administrative region.” Its semi-autonomy had been eroding for years at the time of Xiao’s arrest, but the erosion had been felt largely at the street-level, among pro-democracy agitators and outspoken booksellers. For the city’s shielded rich, the dramatic seizure of one of their own sounded a shrill wake-up call.  The Committee for Safeguarding Natio