The United States has accused mainland China of hiring an American citizen of Chinese origin to surveil the family of Taiwanese leader William Lai Ching-te, days after President Xi Jinping’s state visit to Washington. The Federal Bureau of Investigation on Sunday arrested 34-year-old Zhang Wanying at Los Angeles International Airport, alleging that she attempted to flee the country and charged her with acting as an unregistered agent for the Chinese government. The FBI accused her of surveilling...