The Line of Actual Control (LAC) is a de facto military boundary separating Indian-controlled territory from Chinese-controlled territory along the disputed Sino-Indian border, and is a geopolitical concept rather than a formally delimited international boundary. The term originated from a 1959 letter by Chinese Premier Zhou Enlai to Prime Minister Jawaharlal Nehru, describing the "line up to which each side exercises actual control". India initially rejected the concept, but the LAC came to refer to the informal cease-fire line that emerged after the 1962 Sino-Indian War.
The LAC is not mutually agreed upon, jointly mapped, or marked on the ground, leading to differing perceptions of its alignment, which is the structural cause of recurring clashes. It spans approximately 3,488 kilometers according to Indian measurements and is divided into the Western (Ladakh), Middle (Himachal/Uttarakhand), and Eastern (Arunachal Pradesh) sectors.
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 committed both sides to strictly respect and observe the LAC, refrain from using or threatening force, and ensure "No activities of either side shall overstep the line of actual control". Crucially, Clause 6 of the 1993 Agreement states that references to the LAC do not prejudice their respective positions on the boundary question. This framework was reinforced by the 1996 Agreement on Confidence-Building Measures in the Military Field.
The LAC is distinct from the Line of Control (LoC), which is the military demarcation line separating Indian- and Pakistani-administered parts of the former princely state of Jammu and Kashmir. Recently, the LAC has seen significant changes following the 2020 Galwan Valley clash. While the core agreements of 1993 and 1996 remain, their provisions were violated by the massing of troops and attempts to unilaterally alter the status quo. A recent development is the October 2024 agreement on patrolling arrangements in Depsang and Demchok, which aims to restore the pre-May 2020 status quo by resuming patrolling and disengaging troops from friction points.