China says the border dispute covers Arunachal Pradesh which it claims as Southern Tibet, India asserts that the dispute covered Aksai Chin area.
In terms of length, India shares 3,488 km of border with China. The Sino-Indian border is generally divided into three sectors namely:
The Western sector,
The Middle sector, and
The Eastern sector.
The Indian boundary with China in the western sector is about 2152 km long. It is between Jammu and Kashmir and Xinjiang (Sinkiang) province of China. India-China Border Dispute UPSC IAS 2018
The middle sector boundary in about 625 km long which runs along the watershed from Ladakh to Nepal.The states of Himachal Pradesh and Uttrakhand touch this border with Tibet (China). This sector does not have any substantial border dispute.
The boundary in the eastern sector is 1,140 km long and runs from the eastern limit of Bhutan to a point near the Talu Pass at the tri-junction of India, Tibet, and Myanmar. This line is called the McMahon Line after Henry Mc Mahon, a British representative who signed the 1913-14 Shimla Convention.
The boundary was established along the Himalayan crest of the northern watershed of the Brahmaputra, except where the Lohit, Dihang, Subansiri, and Kemang rivers break through that watershed.
China considers the McMahon Line illegal and unacceptable claiming that Tibet had no right to sign the 1914 Convention held in Shimla which delineated the Mc Mahon line on the map.
Tawangis central to the resolution of India-China border dispute.
According to China, if India returns Tawang, which is a sacred place for Tibetan Buddhists, it would settle border disputes in western & central boundaries. India, of course, has denied the proposal claiming Tawang to be an integral part of Arunachal Pradesh & India.
The territorial dispute over Aksai Chin can be traced back to the failure of the British Empire toclearly demarcate a legal border between its Indian colony and China.
As two borders between India and China were proposed during the time of the British Raj – the Johnson’s Line and the McDonald Line.
The Johnson’s line shows Aksai Chin to be under Indian control whereas the McDonald Line places it under Chinese control.
India considers the Johnson Line as the correct, rightful national border with China, while on the other hand, China considers the McDonald Line as the correct border with India.
The line that separates Indian-administered areas of Jammu and Kashmir from Aksai Chin is known as the Line of Actual Control (LAC) and is concurrent with the Chinese Aksai Chin claim line.
China and India went to war in 1962 over the disputed territory of Aksai Chin. India claimed this was a part of Kashmir, while China claimed it was a part of Xinjian