Indo China war of 1962
http://www.globalsecurity.org/military/world/war/indo-prc_1962.htm The Chinese have two major claims on what India deems its own territory. One claim, in the western sector, is on Aksai Chin in the northeastern section of Ladakh District in Jammu and Kashmir. The other claim is in the eastern sector over a region included in the British-designated North-East Frontier Agency, the disputed part of which India renamed Arunachal Pradesh and made a state. In the fight over these areas, the well-trained and well-armed troops of the Chinese People's Liberation Army overpowered the ill-equipped Indian troops, who had not been properly acclimatized to fighting at high altitudes.
Unable to reach political accommodation on disputed territory along the 3,225-kilometer-long Himalayan border, the Chinese attacked India on October 20, 1962. At the time, nine divisions from the eastern and western commands were deployed along the Himalayan border with China. None of these divisions was up to its full troop strength, and all were short of artillery, tanks, equipment, and even adequate articles of clothing.
In Ladakh the Chinese attacked south of the Karakoram Pass at the northwest end of the Aksai Chin Plateau and in the Pangong Lake area about 160 kilometers to the southeast. The defending Indian forces were easily ejected from their posts in the area of the Karakoram Pass and from most posts near Pangong Lake. However, they put up spirited resistance at the key posts of Daulat Beg Oldi (near the entrance to the pass) and Chushul (located immediately south of Pangong Lake and at the head of the vital supply road to Leh, a major town and location of an air force base in Ladakh). Other Chinese forces attacked near Demchok (about 160 kilometers southeast of Chusul) and rapidly overran the Demchok and the Jara La posts.
In the eastern sector, in Assam, the Chinese forces advanced easily despite Indian efforts at resistance. On the first day of the fighting, Indian forces stationed at the Tsang Le post on the northern side of the Namka Chu, the Khinzemane post, and near Dhola were overrun. On the western side of the North-East Frontier Agency, Tsang Dar fell on October 22, Bum La on October 23, and Tawang, the headquarters of the Seventh Infantry Brigade, on October 24. The Chinese made an offer to negotiate on October 24. The Indian government promptly rejected this offer.
With a lull in the fighting, the Indian military desperately sought to regroup its forces. Specifically, the army attempted to strengthen its defensive positions in the North-East Frontier Agency and Ladakh and to prepare against possible Chinese attacks through Sikkim and Bhutan. Army units were moved from Calcutta, Bihar, Nagaland, and Punjab to guard the northern frontiers of West Bengal and Assam. Three brigades were hastily positioned in the western part of the North-East Frontier Agency, and two other brigades were moved into Sikkim and near the West Bengal border with Bhutan to face the Chinese. Light Stuart tanks were drawn from the Eastern Command headquarters at Calcutta to bolster these deployments.
In the western sector, a divisional organization was established in Leh; several battalions of infantry, a battery of twenty-five-pounder guns, and two troops of AMX light tanks were airlifted into the Chushul area from Punjab. On November 4, the Indian military decided that the post at Daulat Beg Oldi was untenable, and its defenders were withdrawn over the 5,300-meter-high Sasar Brangsa Pass to a more defensible position.
The reinforcements and redeployments in Ladakh proved sufficient to defend the Chushul perimeter despite repeated Chinese attacks. However, the more remote posts at Rezang La and Gurung Hill and the four posts at Spanggur Lake area fell to the Chinese.
In the North-East Frontier Agency, the situation proved to be quite different. Indian forces counterattacked on November 13 and captured a hill northwest of the town of Walong. Concerted Chinese attacks dislodged them from this hard-won position, and the nearby garrison had to retreat down the Lohit Valley.
In another important section of the eastern sector, the Kameng Frontier Division, six Chinese brigades attacked across the Tawang Chu near Jang and advanced some sixteen kilometers to the southeast to attack Indian positions at Nurang, near Se La, on November 17. Despite the Indian attempt to regroup their forces at Se La, the Chinese continued their onslaught, wiping out virtually all Indian resistance in Kameng. By November 18, the Chinese had penetrated close to the outskirts of Tezpur, Assam, a major frontier town nearly fifty kilometers from the Assam-North-East Frontier Agency border.
The Chinese did not advance farther and on November 21 declared a unilateral cease-fire. They had accomplished all of their territorial objectives, and any attempt to press farther into the plains of Assam would have stretched their logistical capabilities and their lines of communication to a breaking point. By the time the fighting stopped, each side had lost 500 troops.
India considers recurring Sino-Indian border clashes a potential threat to its security. Since the war, each side continued to improve its military and logistics capabilities in the disputed regions. China has continued its occupation of the Aksai Chin area, through which it built a strategic highway linking Xizang and Xinjiang autonomous regions. China had a vital military interest in maintaining control over this region, whereas India's primary interest lay in Arunachal Pradesh, its state in the northeast bordering Xizang Autonomous Region.
In 1987, although India enjoyed air superiority, rough parity on the ground existed between the two military forces, which had a combined total of nearly 400,000 troops near the border. The Indian Army deployed eleven divisions in the region, backed up by paramilitary forces, whereas the PLA had fifteen divisions available for operations on the border. After a 1986 border clash and India's conversion of Arunachal Pradesh from union territory to state, tensions between China and India escalated. Both sides moved to reinforce their capabilities in the area, but neither ruled out further negotiations of their dispute. Most observers believe that the mountainous terrain, high-altitude climate, and concomitant logistic difficulties made it unlikely that a protracted or larges-cale conflict would erupt on the Sino-Indian border.
Negotiations since the 1962 Sino-Indian border war have taken place to resolve the conflicting border claims. After more than thirty years of border tension and stalemate, high-level bilateral talks were held in New Delhi starting in February 1994 to foster "confidence-building measures" between the defense forces of India and China, and a new period of better relations began.