Think about train derailments and food processing fires. Accidental? Think about the thousands of Chinese military personnel steaming through open borders. Think about how they have set up police infrastructure to track down and punish their own dissidents––in the U.S.
Think about critical infrastructure and consider what they will unleash in America if China decides to move against Taiwan and desires to distract and destabilize the United States right before they strike.
Of course, this is all conjecture, but possible nonetheless.