Answer by Bhupesh Joshi:
To Understand the Sino-India war we will have to study the history of the conflict zones between these two mighty countries. There were/are mainly two conflict zones 1. On the eastern sector (parts of Arunachal Pradesh(or Tawang region)) 2. On the western sector (Aksai Chin)
Though there are other regions also, like the parts of Himanchal Pradesh and Uttarakhand (or Nilang and Lapthal) but these are not of much concern.
1. In the Eastern region: The British had drawn the McMohan line to protect the tea estates of the province of Assam from the raiders of North. There was an "Inner line" below the McMohan line beyond which no one could venture without permit.
Between this region of the "Inner line" and the border lived many self administered and self-contained tribes. Some of them were Buddhist which mainly lived around the monastery at Tawang. It paid tribute to Tibetan authority and was 'ecclesiastically subject' to Lhasa.
After the Shimla Accord, the British persuaded the Tibetans to give away the control of area near Tawang and in this way came up the McMohan Line which extended the Indian border. So technically it was only after 1914 the Tawang region became a part of the India. The basic idea of the British administration was that if some day China again gains control of Tibet then there should be some part of Tibet that is under the British control so as to separate the planes of Assam (read tea estates) from the plateau (and to not give the Chinese advantage of height).
When the new government was formed in Delhi it inherited the British borders. In February 1951 a small force accompanied by political and administrative officers reached Tawang and instructed the Lamas that they need not pay tribute to Lhasa. This region became the part of North East Frontier Agency (NEFA) and gradually the administrative gap was filled by the Indian officials.
So the question that pops up now is while all this was going on, was China sleeping. Why didn't it object then and there the presence of Indian officials?
No, obviously Chou En-Lai (read China) was not sleeping and we must keep in mind that it was 1950's and not 2014 where a lama would have tweeted "Yipee got Indian citizenship". Many historians believe that Chinese for long had no idea of the Indian presence in the Tawang region whereas many believe that they deliberately ignored the Indian presence in the Tawang region to consolidate their claim in the western part. Moreover the newly born Chinese state was busy unifying itself after the communist taking on Beijing in 1949.
2. In the Western region: Like eastern region, in the western region too, the adjoining Indian territory was predominantly Buddhist (region of Ladakh). However Ladakh in past was an independent state and for more than past 150-200 years was a part of the Kashmir state. Between Ladakh and the Chinese province of Sinkiang lay a barren land called "Aksai Chin". It was mainly used by the Ladakhi people for occasional grazing and salt collection. By an agreement of 1842 this part was identified to be the part of Kashmir (which was accepted by British).
However this region was of utmost importance to the Chinese. The Aksai Chin joined their Tibet and Sinkiang provinces of China thus providing a direct geographical continuity.
Here I would like to disagree with Mrthat India had a weaker claim over Aksai Chin region. No official Chinese Map showed Aksai Chin as part of China before 1920 (Source: Himalayan Battleground: Sino Indian Rivalry in Ladakh). Though of less strategic importance, India had a stronger case in the western sector (where the part was with Kashmir for long) than in the eastern sector which British acquired after 1914 and where Indians entered after 1951.
In 1956 China began building a road across Aksai Chin and by October 1957 the road was ready to carry heavy army trucks to Lhasa.
Let us ask the same question to India. Was India sleeping while China was busy building a road?
And the answer is known. Yes for the first half of 1956 we were sleeping and had no idea (or rather ignored it as our defense minister didn't consider China as a threat). In later half Indian diplomats were busy peacefully negotiating with their Chinese counter parts.
Since we now broadly know the basis of dispute, we will try to answer as to
Why did China invade India?
Though India has no answers and China have always kept silence on the reasons of the war, it can be easily understood by the result of the war. As written by a historian:
On 21 November 1962, China unexpectedly announced to the world that it was declaring a unilateral cease-fire on the Sino-Indian border and, beginning 1 December 1962, would withdraw its troops 20 kilometres from the Line of Actual Control [LAC] existing between the two countries as on 7 November 1959. It was further clarified that in the eastern sector, Chinese troops would withdraw 20 kilometres north of the ‘so-called McMahon Line.’ With this announcement, the fighting in the brief Sino-Indian border conflict came to an end since India did not challenge the Chinese unilateral ceasefire declaration, nor did it hinder or obstruct the withdrawing Chinese troops. All Chinese troops were north of the McMahon Line by 1 March 1963.
Why did the Chinese retreat?
There are many speculations to this but if we analyse the net gain in terms of territory for China, it was an insignificant (for India) 2,000 square kilometers of alpine desert in Ladakh. China invaded India only to get the part that was strategically important to it. It provided China a geographical continuity and an easy excess to its disturbed state of Tibet. As early as in 1956 on his visit to China Mr. Nehru was told that though Chinese considered the McMohan Line an imperial British legacy but "only because of friendly relations" with India, the Chinese would give it recognition.
This is more clearly expressed by the Chinese primer Mr. Chou En-Lai himself on his visit to India in 1960. He said to Mr. Nehru that 'neither side should put forward claims to an area which is no longer under its administrative control'. He further added 'in the eastern sector, we acknowledge that what India considers its border has been reached by India's actual administration. But, similarly we think that India should accept China's administration has reached the line which it considers to be her border in the western sector'. (Source: India After Gandhi by Ramachandra Guha)
The Chinese always wanted a status quo (that they will not cross McMohan Line and India must not come to the Aksai Chin region). Many (rather overwhelming) historians believe that China always wanted to legitimize and maintained the status quo. Weather by dialogue or by war it was upto India.
Cease-fire after war was a way to maintain status quo. After all breaking it would mean going into war with China. Retreating behind the McMohan line was also and important move by China. Leaving back what it had captured on one hand legitimized the Chinese stand (remember what Mr. Chou had said to Mr. Nehru) and gaining it sympathies and on other hand achieving what it always wanted.
If you sit back and think the war could have been avoided had India (Government(which tried to be historical and philosophical rather than practical) + Opposition(which was in a way on government's neck)) acted according to the need of the hour. The only possible solution would have been India giving away its claim for Aksai Chin and China giving away its claim to the Tawang region (Mr. Nehru was at a time seriously thinking of it).
Though status quo is also the same but it came up on the lives of 1383 Indian soldiers. Moreover it is not permanent and will always be a reason of conflict between the two countries (even for the generations to come).