thumb|Line of Actual Control between China and India (map by the [[Central Intelligence Agency|CIA)]]

thumb|The western portion of the Line of Actual Control, separating the [[Leh district|Eastern Ladakh and Aksai Chin. In the southern Demchok region, only two claim lines are shown (map by the CIA).]]

thumb|The Line of Actual Control vs the legally claimed McMahon Line in Arunachal Pradesh.

The Line of Actual Control (LAC), in the context of the Sino-Indian border dispute, is a notional demarcation line that separates Indian-controlled territory from Chinese-controlled territory on their mutual border. The concept was introduced by Chinese premier Zhou Enlai in a 1959 letter to Jawaharlal Nehru as the "line up to which each side exercises actual control", but rejected by Nehru as being incoherent.

The LAC is different from the borders claimed by each country in the Sino-Indian border dispute. The Indian claims include the entire Aksai Chin region and the Chinese claims include Arunachal Pradesh/Zangnan. These claims are not included in the concept of "actual control".

The LAC is generally divided into three sectors:

  • the western sector between Ladakh on the Indian side and the Tibet and Xinjiang autonomous regions on the Chinese side. This sector was the location of the 2020 China–India skirmishes ;
  • the middle sector between Uttarakhand and Himachal Pradesh on the Indian side and the Tibet autonomous region on the Chinese side ;
  • the eastern sector between Arunachal Pradesh/Zangnan on the Indian side and the Tibet autonomous region on the Chinese side. This sector generally follows the McMahon Line.

The term "line of actual control" originally referred only to the boundary in the western sector after the 1962 Sino-Indian War, but during the 1990s came to refer to the entire de facto border.

Overview

The term "line of actual control" is said to have been used by Chinese premier Zhou Enlai in a 1959 note to Prime Minister of India Jawaharlal Nehru. The boundary existed only as an informal cease-fire line between India and China after the 1962 Sino-Indian War. In 1993, India and China agreed to respect the "Line of Actual Control" in a bilateral agreement, without demarcating the line itself.

In a letter dated 7 November 1959, Zhou Enlai proposed to Jawaharlal Nehru that the armed forces of the two sides should withdraw 20 kilometres from the so-called McMahon Line in the east and "the line up to which each side exercises actual control in the west". Nehru rejected the proposal stating that there was complete disagreement between the two governments over the facts of possession: