China has exploited the crisis in Gaza to present itself as a defender of the Palestinians and a champion of the oppressed. That posture appears to be benefiting China in its geopolitical competition with the United States—even though Beijing is guilty of human-rights abuses against a Muslim community within its own territory. The Uyghurs of China suffer mass detention, population suppression, and cultural assimilation under a brutal authoritarian regime. Yet few protests on university campuses demand their freedom, nor do major diplomatic efforts seek to alleviate their misery.How does China…