The Chinese army’s killing of at least 20 Indian soldiers this week was alarming and unacceptable.

The soldiers were killed in a skirmish along the contested “line of control” of far-northern India and far-western China. Tensions have always ebbed and flowed here, but this is the first loss of life there in 45 years. A conflict between two nuclear powers that comprise more than one-third of the world’s population is no mere sideshow. And China’s attempt to blame India for the deadly fracas should not be taken seriously.