Five thousand five hundred metres above sea level, the Indian Air Force Mi4 medium-lift helicopter fought its way over the great ice sheets shrouding Ladakh, its single radial engine rendered asthmatic by altitudes its Soviet designers had never designed it to perform. Evading bursts of small-arms fire sent their way by People’s Liberation Army patrols perched along the Galwan river, the pilots slowly made their way to the Indian Army’s eastern-most outpost in Ladakh. There was, the pilots would report that morning of 21 October, 1962, no sign of life: Galwan Post, India’s most remote outpost in Ladakh, had been...