On a snowy afternoon in January, 24-year-old Thanujan Sellathurai delivered a speech in front of a small crowd of protesters from the Tamil community in Geneva. He called for the United Nations, which has several of its agencies headquartered there, to condemn the “brutal atrocity” that had just taken place in Sri Lanka.

Authorities at the University of Jaffna, on the northern tip of Sri Lanka, had ordered the bulldozing of a memorial paying tribute to the victims of the Mullivaikkal massacre, a mass killing of Tamil civilians that took place in May 2009, during the last few days of the country’s civil war. The monument had been built by the university’s own students and other locals in Jaffna, and showed blue arms reaching out of a pile of rubble. ...