INTERNATIONAL EFFORTS to hold China accountable for its campaign of cultural genocide against Uighur and other Muslim minorities have been weak, in part because it’s not easy for outsiders to target concentration camps holding hundreds of thousands of people in the sprawling and remote Xinjiang region. But there is one way to respond to this extraordinary human rights crime that is both straightforward and morally imperative: Western companies must stop importing and marketing goods produced by Uighur forced labor.