Confrontation at Thag La Ridge assumes historical importance in the events that triggered the Sino-Indian conflict leading to War in 1962.
The Chinese perceived the Indian foreign policy favouring independence of Tibet for its own political motives. Other than this the ambiguity in demarcation of the boundary line between China and India and perception to the Chinese about the Indian Forward Policy of 1961 acted as a flash in the pan to ignite the circumstances that led to culmination of a war between the two nations.
Thag La is a name given to a ridge that runs eastward immediately north of the McMahon Line as originally drawn on the map. The Indians have always believed and claimed that the Indian Border with China should run through the highest ridges of the Himalayas owing to the areas south of the Himalayas to be falling traditionally under Indian territory. Accordingly as per Indian belief, the McMahon Line fell south of the Indian Boundary claims. As a result of this belief, The Thag La Ridge -the highest in the area was the preferred by the Indian troops for surveillance as its frontier in preference to the lower ridge to the south falling on the McMahon Line.
Gradually as a part of the implementation of the forward policy, the establishment of a post was ordered at Che Dong in the Valley of Namka Chu River, south of the Thang La ridge in the Tawang Tract. This new post was named as Dhola on account of the ridge on behind and was established on the south side of the Namka Chu River during June, 1962. The post was originally intended at the junction of the frontiers of Tibet, Bhutan and Assam at the western end of the ridge, because in the opinion of the patrol leader the ridge lay north of the Mc Mohan line as shown on the map.
The Chinese reacted strongly on 8th September 1962 with placement of and mobilisation of its troops moving over and down the Thag la ridge and established them in dominating positions at the Dhola Post. On 11 September, it was decided by the Indian Army to give permission to all forward posts and patrols to fire on any armed Chinese who entered Indian Territory which led to the infamous confrontation at Thag La between the armies of the two countries.
It is believed by the historians that on account of shoddy planning s by policy makers, severity and toughness of the conditions of the terrain, requirements of long treks and burden of excessive weight of transporting the arms the Chinese troops gained advance over the Indian army and gained control over both the banks of the Namka Chu River resulting in a series of Confrontation at Thag la.
On 20 September, Chinese started grenade attack at Indian troops and a fire fight developed, triggering a long series of skirmishes and finally culminated into a full-fledged war in October 1962 even after visit and assurances of Chinese leader Zhou Enlai to New Delhi.
Some historians and critics believe that Confrontation at Thag La could have been avoided had the Indian army restricted its movements within the boundaries of the demarcated McMahon Line.
The confrontation at Thag La ridge and the War resulting as an aftermath held grave consequences for India and later resulted in development and implementation of new foreign policies and military development strategies.