Published Date: September 17, 2026
What is the history of the Line of Actual Control (LAC), how have the countries attempted to manage border issues in the past, and why does China continue to lay claims on Arunachal Pradesh? Former diplomat Ashok K Kantha explains.
Rishika Singh
New Delhi, December 23
Last month, India and China again exchanged strong statements over Arunachal Pradesh, after a woman born in the state was arbitrarily detained at the Shanghai International Airport.
China’s claims on Arunachal Pradesh are part of the larger, decades-old boundary dispute with India. Ashok K Kantha, a former diplomat and Ambassador to China, who participated in several rounds of border talks, outlines the dispute. He is now Subhas Chandra Bose Chair of International Relations at Chanakya University and Distinguished Fellow at Vivekananda International Foundation.
What is the history of the India-China Line of Actual Control (LAC)? China says that it never accepted the McMahon Line boundary. Can you explain the background of these differences.
Let me begin with the McMahon Line. It traces its origins to the Simla Conference of 1913–14, where representatives of British India, Tibet and China participated as equal and fully empowered Plenipotentiaries. British India was represented by Henry McMahon, Tibet by Lonchen Shatra and China by Ivan Chen.
The traditional boundary in the Eastern Sector was formalised by an exchange of letters and appended maps between Indian and Tibetan Plenipotentiaries on 24 March and 25 March 1914. Tibet was at that time fully entitled to enter into treaties. The Chinese government had recognised these rights and was aware of the formalisation of the Indo-Tibetan boundary at the Simla Conference.
All three representatives initialled the draft Simla Convention on 27 April 1914. When the final Convention was presented for signature on 3 July 1914, only the Plenipotentiaries of British India and Tibet signed. The Chinese Plenipotentiary refused to sign, but his objection did not relate to the India–Tibet boundary at all. Ivan Chen raised no protest against the McMahon Line during the negotiations. All Chinese reservations were regarding the boundaries of “Outer Tibet” and “Inner Tibet.” Ivan Chen did not object to the boundary shown on the Convention map between India and Tibet.
After the fall of the Qing dynasty, China did not exercise any control over Tibet – even earlier, links were ambivalent. For several decades, Tibet maintained its own government, conducted its own external dealings, and administered its territory independently. It was only in 1950, when Chinese forces entered Tibet, that Beijing established direct control. This historical reality underscores that the McMahon Line was negotiated between British India and the competent Tibetan authority of the time, and that China’s later objections were unrelated to the India–Tibet boundary drawn at Simla.
As for the history of India-China “Line of Actual Control” (LAC), this concept was first mentioned by the Chinese Premier Zhou Enlai in his letter dated 7 November 1959 to Jawaharlal Nehru. Zhou described it as the line up to which each side exercised actual control. He proposed that the armed forces of China and India each withdraw 20 kilometres from the McMahon Line in the East and from the line up to which each side exercised actual control in the West. This was not acceptable to Nehru. Nehru also rejected the concept of the LAC as proposed by Zhou.
However, an LAC did emerge as fait accompli after the Chinese invasion of 1962 and their subsequent withdrawal in the Eastern Sector. In the Western Sector, the Chinese occupied of territories compared to where they were on 7 November 1959 and the alignments as shown in their maps of 1956 and 1960.
Zhou Enlai’s letter of 15 November 1962, addressed to the Heads of Government of Asian and African countries, reiterated the proposal for adherence to the so-called “LAC of 7 November 1959,” which was shown on a small-scale map appended to the letter. India found this proposal unacceptable, as it would have legitimized Chinese occupation of Aksai Chin.
Moreover, the Chinese concept of the “LAC of 7 November 1959” was a flexible and movable construct with deliberate ambiguity.
In the Western Sector, the LAC was supposed to coincide with the Chinese claim line, which had shifted significantly to India’s disadvantage since 1956. It included Chinese claims beyond what they occupied in 1962, extending into areas controlled by India.
In the Eastern Sector, China agreed that the LAC coincided with the McMahon Line, but there were major differences on interpretation of the Line. The Chinese argued illogically for a literal interpretation based on the original maps and transposing them onto contemporary maps. India has maintained that the boundary line as shown on small-scale Simla Conference maps must be interpreted on the basis of its underlying principle, that is, the highest watershed of the region.
In Sikkim, China accepted the watershed boundary based on the Anglo-Chinese Convention of 1890 but claimed pockets on the Indian side of the watershed.
In the Middle Sector, China claimed some pockets south of the watershed, further complicating the boundary dispute.
How did India and China come to an understanding on the LAC?
India formally accepted the concept of LAC during negotiations leading up to the Border Peace and Tranquility Agreement of September 1993. It was a pragmatic change in India’s position. Border areas had turned live after the Chinese encroachment in Wangdung in the Eastern Sector and our forceful response involving forward deployment of troops in 1986-87. Prime Minister Rajiv Gandhi’s visit to China in December 1988 stabilised the relationship but border tensions had underlined the urgency of developing an architecture for maintenance of peace and tranquility. Pending a boundary settlement, both sides agreed to respect and observe the LAC. It is important to note that we accepted the construct of LAC but specifically rejected the Chinese concept of “LAC of 7 November 1959”. The LAC is based on actual control, and not some notional or historical alignment
The concept of LAC was incorporated in the Agreement on Maintenance of Peace and Tranquillity in Border Areas signed during Prime Minister PV Narasimha Rao’s visit to China in September 1993. I assisted in those negotiations as Director (China) in Ministry of External Affairs. Article 1 of the Agreement says that pending an ultimate boundary settlement, both sides will strictly respect and observe the line of actual control and that no activities of either side shall overstep the LAC.
This path-breaking agreement bacame the basis for developing an elaborate architecture of confidence building measures (CBMs) which by and large ensured peace in border areas, notwithstanding occasional standoff situations. This of course changed completely after Chinese transgressions in Eastern Ladakh and the deadly Galwan clash on 2020.
Returning to our earlier narrative, we signed another important agreement on military CBMs in November 1996, for which I was the lead Indian negotiator. Apart from a set of CBMs, this agreement also contains a commitment to move towards a common understanding of the LAC. It was our assessment that ambiguity on the LAC could be risky and also allow the Chinese to seek incremental gains.
I found that the Chinese were reasonable in those negotiations and they responded positively to our suggestion regarding seeking “common understanding” of the LAC as a pratical requirement.
Thus, Article10 provides, “Recognizing that the full implementation of some of the provisions of the present Agreement will depend on the two sides arriving at a common understanding of the alignment of the line of actual control in the India-China border areas, the two sides agree to speed up the process clarification and confirmation of the line of actual control.” They also agreed to “exchange maps indicating their respective perceptions of the entire alignment of the line of actual control as soon as possible.”
However, the exchange of maps didn’t proceed smoothly. By 2002, we had exchanged maps of the Middle Sector which showed some Chinese claims south of the watershed boundary. However, we are in effective control of the LAC as projected by us in the Middle Sector, though there are occasional Chinese intrusions in Barahoti in particular.
Maps were prepared for the Western Sector, but China refused the exchange, saying India had inflated its claim. Indian officials pointed out that India also found their maps unacceptable, but the whole idea was to exchange maps showing respective perceptions. By then, they had concluded that they did not want to proceed with clarification and maintain ambiguity. They told us they were worried that if they confirmed the LAC, they would be freezing the border, and it would become the boundary.
The process broke down around 2004, and since then, there has been no forward movement on LAC clarification.
The bottomline is that the Chinese are using ambiguity on the LAC and unsettled borders as a major pressure point against us.
How has India responded to China’s claims on Arunachal Pradesh?
Despite China’s claims on Arunachal Pradesh, we are in effective control up to the watershed boundary. There are only three pockets where they are in what we call “adverse possession”— parts of Namka Chu Valley, Sumdorong Chu Valley and Longju. They concede that the rest is with us, but differences on the interpretation of the McMahon line persists and there are probings by the Chinese side from time to time. We cannot rule out Eastern Ladakh type operations across LAC in the Eastern Sector.
I remain concerned about the Eastern Sector because they have gradually resurrected their claims over large tracts in Arunachal Pradesh.
During his visit to India In 1960, Zhou Enlai had told Nehru that though China didn’t recognize McMahon Line it was prepared to take a “realistic view” and that after settlement, the Chinese map will be changed more. He had implied Chinese accommodation of Indian claim in Eastern Sector, provided India was willing to accommodate Chinese claim in Western Sector. Zhou’s six common points or points of proximity not acceptable to India.
During then Foreign Minister Atal Bihari Vajpayee’s visit in 1979, Deng Xiaoping offered his “package proposal”, under which China would compromise in the Eastern Sector and India in rest, and there would be “small adjustments” within this “big adjustment”. In an interview to Vikrant in June 1980, Deng made an offer in the public domain: China will make concessions in Eastern Sector and India in Western Sector on the basis of actually controlled border line to solve boundary question in a package plan.
In 1985, the Chinese introduced a completely contrary proposition. They said the area of “greatest difference” was in the Eastern Sector and India must make “substantive concessions” there and only then would China make “corresponding concessions” in the Western Sector. This was obviously unacceptable to us.
During negotiations on the Agreement on the Political Parameters and Guiding Principles for Boundary Settlement, for which I was the lead Indian negotiator, they again pressed for their proposition on “Dong Tiao Xi Rang” (adjustments by India in the East, and concessions by China in the West), which was rejected by us. We made it clear that we did not have flexibility in the East and that our adjustments would come in the West. In order to protect our interests in respect of Tawang, which the Chinese have been claiming, we insisted on a provision which Chinese accepted most reluctantly. This is Article VII which was the last article to be finalised, which reads, “In reaching a boundary settlement, the two sides shall safeguard due interests of their settled populations in the border areas.”
And yet, the Chinese soon resurrected their terminology of “Zangnan” or “South Tibet” for Arunachal Pradesh. Their claims are now being reiterated more stridently and accompanied by measures like renaming of places in Arunachal as also harassment of Indian nationals from Arunachal Pradesh, like the recent detention of an Indian national just transiting through Shanghai. Following this incident, their official spokesperson reiterated the Chinese position on Arunachal Pradesh.
I have argued that we should take China’s claims seriously and take counter-measures through an asymmetric deterrence strategy. India should not pretend that this is just a negotiating ploy. It’s a serious claim on their part, with concomitant risks involved.
Has the frequency with which such claims are being raised increased?
Over the past decade or so, China has become more aggressive in projecting and unilaterally asserting its contested territorial claims. They engage in “salami slicing” or “grey zone operations”, where they incrementally change the situation on the ground through coercive means staying under the threshold of an outright military conflict. The altered facts becomes the “new normal” and a base for further changes. This strategy has been deployed in different theatres, including South China Sea, East China, Taiwan Strait and along the India-China borders. This has been done most effectively in the South China Sea.
Even in Eastern Ladakh, there is still unfinished business of disengagement as there are continuing restrictions on patrolling by Indian troops and grazing activities of Indian herdsmen to areas they were traditionally visiting in the “buffer zones”. If these arrangements become permanent, the Chinese side would have partially achieved its objective of making incremental changes in the ground situation. It will not be in India’s interests to let the present situation freeze and become the “new normal”.
Another big change must be considered — during previous discussions, both sides were clear about differentiating the LAC from sovereignty-related issues. China no longer maintains that differentiation. President Xi Jinping has said, they will not cede “an inch of territory”. Does it apply to the LAC as well?
Aggressive pursuit of contested territorial claims is a risky strategy on China’s part, but they have persuaded themselves to proceed with it, even if there may be some loss of reputation and an impact on their relations with other countries. China cannot forcibly achieve its claim on Arunachal Pradesh but we must always guard against probing operations.
The 2005 agreement stipulated that an early settlement of the boundary question will advance the basic interests of the two countries and should therefore be pursued as a strategic objective. Today, China is no longer interested in that. They believe time is on their side, and maintaining a degree of pressure on us in border areas doesn’t hurt.