Americans know Jackie Chan best for his cheery, acrobatic performances in action movies such as “Rumble in the Bronx” and “Rush Hour,” made successful by his amazing martial artistry and self-effacing comedy. Chinese know Chan, a Hong Kong native, for largely the same reasons. But they also know him for something most Americans might find surprising: He is passionately political, a staunch defender of the Chinese Communist Party and harsh critic of anyone he sees as opposing Beijing. Today, that includes the United States. Chan, responding to widespread criticism of China’s recent censorship of a popular newspaper, insisted in a...