PROGRESS WATCH Two decades after a landmark treaty, and despite an overall increase due largely to Syria’s civil war, the majority of affected countries recorded fewer deaths linked to land mines and cluster munitions. In January 1997, Diana, princess of Wales, famously walked through an active minefield in Angola to raise awareness of the ongoing threats posed by land mines. During her visit, with the help of a removal expert, Diana detonated one of the remaining mines. “One down, 17 million to go,” she said while pushing the button. This year marked the 20th anniversary of the death of...