China has turned up the volume with its complaints that the world applies a double standard when it comes to terrorism.

At a daily press briefing on Wednesday, a spokeswoman for China’s Ministry of Foreign Affairs departed from the event’s usual curt, vague answers to criticize a French publication for a recent article on China’s Xinjiang region, where some among the mainly Muslim Uighurs are staging anti-government violence. The article looks at China’s policies that may be driving resentment among Uighurs and says the government...