The report finds that China’s government is deliberately trying to “destroy” the Uyghur ethnic group, contravening every provision of the Genocide Convention that it has ratified. Up to 2 million Uyghurs have been detained in camps in the northwestern province and former detainees have testified to indoctrination, sexual abuse and forced sterilization. China denies human rights abuses and says the centers counter religious extremism and terrorism.

In Washington, few doubt what is going on: On its last day, the Trump administration belatedly declared a genocide (after the ex-President soft-pedaled the issue while pursuing a trade deal with China). President Joe Biden came to an identical conclusion while he was a candidate. Now the US response is on him.

But the world has struggled before to mobilize against genocide even in small nations without China’s vast clout, like Bosnia or Rwanda. In this case, there’s no chance of a military response to stop the torment of the Uyghurs. And…