Tensions sharply worsened from 2009, when Uighurs taking part in ethnic riots killed about 200 Han in Urumqi, the regional capital, after earlier tensions and violence. Chinese security forces began a sweeping crackdown. Attacks and more crackdowns occurred across Uighur towns in the years afterward, as well as in some cities outside Xinjiang.
Since 2017, Xinjiang leaders pressed by Mr. Xi have begun or stepped up policies intended to transform the Uighurs, Kazakhs and other ethnic minorities into loyal, largely secular supporters of the Communist Party. The State Department determination said the Chinese government had committed “crimes against humanity” since “at least March 2017.”
Security forces have sent hundreds of thousands of Uighurs and Kazakhs — possibly a million or more by some estimates — to indoctrination camps intended to instill loyalty to the party and break down adherence to Islam. The Chinese government has defended the camps as benign vocational training schools and disputed the estimates of inmate numbers, without ever giving its own. Former inmates and their families who have left China have described harsh living conditions, crude indoctrination and abusive guards.
The swelling camps drew growing international condemnation, including from human rights experts who advise the United Nations as well as the United States and other nations. Journalists and scholars began writing articles on the camps and a sophisticated high-tech surveillance system in Xinjiang in 2017, well before foreign governments started discussing the issue.
The indoctrination camps, however, have formed only part of the Chinese Communist Party’s broader campaign to drastically transform Uighurs, Kazakhs and other ethnic minorities. Other measures include labor transfers, schooling and cultural policies, and population controls.
Under Mr. Xi, Xinjiang has expanded and intensified longstanding programs to shift Uighurs and Kazakhs from rural areas to jobs in factories, cities and commercial farming. The Chinese government has said that these work transfers are entirely voluntary and bring prosperity to impoverished peoples. But some programs have set targets for the numbers of people relocated for work and restricted recruits from choosing or leaving their jobs — hallmarks of forced labor.
Schools have largely discarded classes in Uighur, pressing students to learn in Chinese. Uighur academics who have sought to preserve and promote their culture have been arrested, and Uighur-language publishing has been heavily curtailed. Officials have forced children into boarding schools, separated from their parents.