The landmark Genocide Convention has had mixed results since the UN approved it 75 years ago

A woman prays in front of skulls at a memorial in Phnom Penh, Cambodia, marking the genocide that happened under the Khmer Rouge regime in the 1970s. Tang Chhin Sothy/AFP via Getty Images

Seventy-five years ago, in the wake of Nazi atrocities, the world made a vow.

Countries pledged to liberate humanity from the “odious scourge” of genocide when, at the United Nations, they established a new convention on preventing and punishing genocide on Dec. 9, 1948.