Sino-Indian border

The Line of Actual Control (LAC) is a demarcation line that separates Indian-controlled territory from Chinese-controlled territory in the former princely state of Jammu and Kashmir.

There are two common ways in which the term "Line of Actual Control" is used. In the narrow sense, it refers only to the line of control in the western sector of the borderland between the two countries. In that sense, the LAC forms the effective border between the two countries, together with the (also disputed) McMahon Line in the east and a small undisputed section in between. In the wider sense, it can be used to refer to both the western line of control and the MacMahon Line, in which sense it is the effective border between India and the People's Republic of China (PRC).

The entire Sino-Indian border (including the western LAC, the small undisputed section in the centre, and the MacMahon Line in the east) is 4,056 km (2520 mi) long and traverses five Indian states: Jammu and Kashmir, Uttarakhand, Himachal Pradesh, Sikkim and Arunachal Pradesh. On the Chinese side, the line traverses the Tibet Autonomous Region. The demarcation existed as the informal cease-fire line between India and China after the 1962 conflict until 1993, when its existence was officially accepted as the 'Line of Actual Control' in a bilateral agreement. However, Chinese scholars claim that the Chinese Prime Minister Zhou Enlai first used the phrase in a letter addressed to Indian Prime Minister Jawaharlal Nehru dated 24 October 1959.

Although no official boundary had ever been negotiated between China and India, the Indian government even today claims a boundary in the western sector similar to the Johnson Line of 1865, whereas the PRC government considers a line similar to the Macartney–MacDonald Line of 1899 as the boundary.

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