> India and China share a disputed 3,440km (2,100-mile) boundary known as the Line of Actual Control (LAC). This de facto border runs through remote and inaccessible natural paths along the Himalayas, passing through rivers, remote mountains and forest cover. It is ill-defined and its demarcations have remained a source of contention between two neighbours who fought a major war in 1962, in which India suffered a humiliating defeat.