The Line of Actual Control (LAC) is a concept that serves as the de facto military boundary separating Indian-controlled territory from Chinese-controlled territory in the context of the Sino-Indian border dispute. It is a notional demarcation line, not a legally recognized international border, and is not mutually agreed upon or clearly delineated on a map. The concept originated with Chinese Premier Zhou Enlai's 1959 letter to Prime Minister Jawaharlal Nehru, proposing a "line up to which each side exercises actual control," a proposal Nehru rejected. The term subsequently came to refer to the informal cease-fire line that emerged after the 1962 Sino-Indian War.
The LAC spans approximately 3,488 kilometers according to India, though China claims it is shorter, around 2,000 kilometers, reflecting their differing perceptions of its alignment. It is generally divided into three sectors: the western sector (Ladakh/Aksai Chin), the middle sector (Uttarakhand/Himachal Pradesh), and the eastern sector (Arunachal Pradesh), which largely follows the McMahon Line.
The mechanism for managing the LAC is primarily governed by bilateral agreements, notably the 1993 Agreement on the Maintenance of Peace and Tranquility along the Line of Actual Control in the India-China Border Areas. This agreement established that neither side would use force or threaten to use force, and that the boundary question would be decided bilaterally. The 1996 Agreement on Confidence-Building Measures further committed both sides to refrain from military activities with high escalatory potential near the LAC.
A related concept is the Patrol Point (PP), which are points along the LAC to which troops patrol, and the limits of patrolling or "actual LAC," which are determined by the terminal location of these PPs.
The LAC has seen significant recent changes, particularly following the 2020 Galwan Valley clash, which resulted in casualties on both sides. This clash led to a series of disengagement agreements at friction points like Galwan, Hot Springs, Gogra, and Pangong Tso, which involved the mutual withdrawal of forward troops and the creation of buffer zones. Recent efforts, including a 2024 agreement, aim to restore pre-2020 patrolling arrangements in areas like Depsang Plains and Demchok. The LAC is distinct from the Line of Control (LoC), which is the military demarcation line between India and Pakistan, formalized by the 1972 Shimla Agreement.