BEIJING — Two Canadians detained in an apparent act of prosecutorial retaliation. A prominent pastor, an internationally renowned Chinese photographer and China’s top international police officer all held by the authorities. Hundreds of thousands of Muslims in the western region of Xinjiang locked up in camps for mass indoctrination.

These and the detentions of many others — including billionaires, lawyers, even the American children of a Chinese fugitive — suggest that the ruling Communist Party no longer cares much about the risk to its international stature posed by harsh actions against its opponents.

Already there are signs that this hard-line approach might be costing China support overseas, alienating even the moderate voices in the United States and elsewhere who have for decades argued that engaging the Chinese leadership is vastly preferable to confronting it.

“It undermines the work of those who have tried to be neutral,” said Kerry Brown, a professor at King’s College, London, and author of a 2016 biography of China’s leader, “C.E.O., China: The Rise of Xi Jinping.”