Many of China’s ethnic Uyghurs clamor to flee the horrors they face in their home country: detainment, torture and “reeducation” in the concentration camps that speckle the western region of Xinjiang. But mounting evidence suggests that even the disfavored minority citizens and persecuted critics who manage to escape China remain within its brutal reach.

Wu Huan, the fiancée of a Chinese dissident wanted for his critical social media posts, fled China for Dubai. She says Dubai police captured her on May 27 and sent her to a secret Chinese-run detainment camp, which held her for eight days. A Chinese officer said she would never leave. In response, Ms. Wu says she began refusing meals, screaming and crying for her release. Ultimately, Chinese camp officers released her after coercing her into signing legal documents incriminating her fiancé.

Based on their distinctive appearance and accent, she claims that her fellow captives were Uyghurs. One screamed, “I don’t want to go back to China; I want to go back to Turkey,” where many Uyghurs have found refuge. If Ms. Wu’s account is true, as the Associated Press says considerable evidence suggests, this is the first known instance of China exporting its “black sites” — secret jails where prisoners are held without charges or hope of trial.

It wouldn’t, however, be the first time the United Arab Emirates did China’s dirty work. In 2018, Emirati police detained a Uyghur man and Chinese citizen, Abudujilili Supi, while he was visiting a Dubai police station to collect paperwork. He hasn’t been seen since. In late 2017 and early 2018, Dubai police arrested and deported at least five Uyghurs — delivering them back into the hands of a country credibly accused of genocide against this minority Muslim community.

These arrests are part of China’s broader effort to harass and repatriate Uyghurs who have escaped the terrors of the Chinese government, and silence its critics. In early 2017, Chinese authorities told Uyghurs with Chinese citizenship living abroad to return to China; many who listened joined the more than 1 million Uyghurs housed in prison camps according to a Freedom House report. Chinese authorities have hunted those who did not return or who have since fled. Thailand alone has deported more than 100 Uyghurs and extradited journalists at Beijing’s request; Egypt has jailed hundreds.

China has invested over $36 billion in UAE infrastructure projects through its Belt and Road Initiative, and the nations have long-standing political ties. In return, Ms. Wu’s allegations suggest that the UAE is not only handing over people the Chinese government wants but also allowing Chinese personnel to operate a clandestine detention camp on its soil.

Not content to terrorize minority communities and critics at home, the Chinese government is exporting repression to countries unwilling or unable to resist. These nations participate in China’s extreme human rights abuses, a moral stain that no amount of infrastructure investment or goodwill curried in Beijing can justify. Countries rightly appalled must preserve bonds of solidarity and cultivate opposition to this growing illiberal menace.