Authored By: Inji Mammadli
Trinity College Dublin
- Introduction
The Sino-Indian boundary dispute remains one of the longest-standing unresolved territorial disputes in contemporary international law. Although often examined through the prism of geopolitics, military strategy, or regional security, the dispute is equally significant as a legal controversy concerning the acquisition and proof of territorial sovereignty. The western sector of the boundary, centred on Aksai Chin, is particularly illustrative in this regard. Unlike many territorial disputes resolved by reference to treaty provisions or clearly demarcated frontiers, the competing claims in Aksai Chin rest upon divergent colonial-era cartography, conflicting historical narratives, and inconsistent patterns of administration. The absence of a mutually recognised delimitation agreement has transformed the dispute into a broader inquiry concerning the legal principles by which sovereignty over disputed territory may be established.
The legal complexity of the western sector is heightened by the historical evolution of the dispute. British India’s frontier policy produced multiple and often contradictory boundary proposals, none of which acquired unequivocal legal status. Following India’s independence and the establishment of the People’s Republic of China, these unresolved colonial legacies became increasingly intertwined with strategic considerations, culminating in the construction of the Xinjiang–Tibet highway, the deterioration of bilateral relations, and ultimately the Sino-Indian War of 1962. Although the conflict fundamentally altered the factual situation on the ground, it failed to settle the underlying legal controversy. More than six decades later, the parties continue to advance competing conceptions of sovereignty while maintaining incompatible understandings of the Line of Actual Control.
This article argues that the legal merits of the competing claims in the western sector cannot be assessed solely through historical maps or political assertions. Rather, they must be examined against the principles governing territorial sovereignty under international law. Particular attention is therefore devoted to the relationship between historical title, cartographic evidence, and the doctrine of effectivités, which has consistently occupied a central position in the jurisprudence of international courts and tribunals when determining sovereignty in the absence of a definitive treaty title. The analysis proceeds from the premise that territorial disputes should be evaluated primarily through established legal principles rather than retrospective political narratives.
The central research question addressed in this article is therefore whether, under the rules of public international law governing territorial sovereignty, the legal arguments advanced by India or China provide the stronger claim to Aksai Chin in the western sector of the Sino-Indian boundary dispute. To answer this question, the article employs a doctrinal legal methodology. It analyses the historical evolution of the competing claims, examines the relevant principles governing territorial acquisition and proof of sovereignty, and evaluates the parties’ arguments in light of international jurisprudence, particularly the case law of the International Court of Justice (ICJ) and earlier international arbitral tribunals concerning territorial disputes.
It is important to delineate the scope of this study. The Sino-Indian boundary dispute consists of three distinct sectors (the western, middle, and eastern sectors), each characterised by different historical circumstances, legal instruments, and competing claims. This article is confined exclusively to the western sector, namely the dispute concerning Aksai Chin. Restricting the analysis in this manner permits a more focused examination of the distinctive legal questions raised by the western sector without conflating them with the substantially different legal and historical considerations governing the remainder of the Sino-Indian boundary.
The article proceeds in four parts. Following this introduction, Part 2 outlines the historical background of the western sector and examines the legal foundations of the competing territorial claims, including the significance of the Johnson and McCartney-MacDonald Lines and the relevance of effective control under international law. It also evaluates the relative strength of the parties’ legal positions. Part 3 offers concluding observations regarding the dispute from the perspective of international law.
- Historical and Legal Origins of the Western Sector Dispute
According to India, the boundary issue in the western sector began with the Chinese construction of an all-weather motorable road in 1956, which ran through Aksai Chin.[1] India saw Aksai Chin as the easternmost section of Ladakh, but China stressed that it had always been under Chinese jurisdiction.[2]
The dispute in this sector is caused by India’s and China’s reliance on two different maps produced by the British before the twentieth century.[3] India bases its territorial claim on the Johnson Line, delineated in 1865 by a British surveyor, which places Aksai Chin entirely within Indian borders.[4] Conversely, China adheres to the McCartney-Macdonald Line of 1899, which incorporates Aksai Chin into Chinese territory.[5]
It is important to note that the controversy over Aksai Chin only arose with the road construction in 1956. India viewed this development as a direct challenge to its territorial integrity,[6] while China asserted that Aksai Chin had always been under Chinese jurisdiction.[7] An analysis of the validity of these claims reveals several critical points.
Foremost, the Johnson Line, despite being the basis for India’s claim, was never depicted on pre-twentieth century official maps.[8] Importantly, it was also never communicated to the Chinese authorities.[9] The Line is also believed to be historically invalid and its cartographical veracity is doubtful.[10]
Conversely, the McCartney-Macdonald Line had been communicated to the Chinese side, and the British subsequently featured it in an authoritative map from 1909.[11] While China did not formally agree to this border delineation,[12] its silence was interpreted as consent to this Line.[13] It is also important to note that the British government of India had followed this Line in the years leading up to 1947.[14]
Post-independence Indian maps initially showed the western sector border as undemarcated;[15] however, this changed in 1954 when India unilaterally modified its map to align with the Johnson Line, without prior consultation with the Chinese side.[16] This stance has remained consistent since 1954: the Indian government at present contends that Aksai Chin constitutes the easternmost section of Ladakh.
- International Law Perspective: Effectivités as Evidence of Territorial Sovereignty
It is this ambiguity surrounding these two lines that engenders significant confusion in this dispute. The absence of a prior treaty that could substantiate either party’s claim further complicates the matter. In such circumstances, where neither party can present a treaty-based claim to the disputed territory, it becomes plausible to assign determinative weight to the principle of effective control or possession. Such possession is founded on elements of proof that are called ‘effectivités’. The latter denotes genuine manifestations of state authority, such as the imposition of laws or taxes, the stationing of troops, and other acts à titre de souverain relevant to the given territory.[17] In other words, those are the acts – legislative, administrative or judicial – demonstrating an effective exercise of governmental authority.[18] However, not every act a party has invoked as an effectivité is inevitably an effectivité admissible as proof of title or exercise of title under international law. To be recognised as effectivités, the acts should be actes publics et paisibles de nature étatique.[19] In the Cameroon/Nigeria case, the ICJ furthermore asserted that effectivités contra legem cannot create a title of sovereignty.[20]
Effective control or possession has been prioritised in ICJ case law. In 2008, the ICJ handed down its decision in a territorial dispute between Singapore and Malaysia, where it considered several factors before weighing the effectivités of the parties.[21] The latter appeared to be decisive, having a direct impact on the outcome of this case. This evinces that, as a catégorie juridique, effectivités prove superior to other, non-legal arguments invoked by the parties. This has been further evidenced by the fact that historical arguments and maps have been rejected by international courts and tribunals as long as they were not backed by evidence of effective possession.[22]
The origin of effective possession as a valid claim may be traced back to the Island of Palmas award of 1928, in which the Permanent Court of Arbitration propounded that the acquisition of title to land required a peaceful and consistent display of state authority.[23] The importance of this element was further reaffirmed in future territorial dispute cases such as the Clipperton Island and the Legal Status of Eastern Greenland, as well as in ICJ case law.[24] Thus, in the Frontier Dispute case, the ICJ postulated that if the legal title is incapable of demonstrating precisely the breadth of territory to which it refers, effectivités can be used to demonstrate how the title is construed in practice.[25] The Court has consistently applied this notion in its case law, including, inter alia, in the Minquiers and Ecrehos case, where the Court decided that the sovereignty over these islands ultimately relies on evidence directly related to the possession of the groups of islets.[26]
Thus, in the absence of a treaty specifically prescribing sovereignty, solid legal claims to territory can be created through demonstrating administrative authority and the exertion of de facto jurisdiction on a continual basis over a long period of time.[27] The legal worth of effectivités in a territorial dispute is therefore determined based on the presence of a legal title. A claim based on effectivités is subordinate to a treaty-based title or other pre-established titles. Thus, if there is a conflict between the title and effectivités, the former will take precedence.[28]
In the Sino-Indian case, since neither India nor China has been able to definitively prove that they have historically administered Aksai Chin, it appears challenging to rely on effectivités when it comes to this region.[29] Nonetheless, facts remain that the Chinese exercised active administrative control over Aksai Chin through the Xinjiang-Tibet highway and Chinese border guards.[30] In contrast, the British India had not dispatched patrols into this region and had not established control over it.[31] There was barely any Indian presence in the area until late 1950s, which explains why India found out about China’s road-building activities, despite their gigantic scale, so late.[32] After independence, Indian officials also accepted that the boundary in Aksai Chin was not defined and it remained unclear which part of it belonged to India.[33] According to Indian historians, there is no basis in treaty, custom or geography to support India’s claim to Aksai Chin.[34]
There is, therefore, no plausible reason why India can accept the Johnson Line but cannot accept the McCartney Line. Even the highway built by the Chinese across Aksai Chin lies above the McCartney Line, which puts it in Chinese territory.[35] In case India recognises the latter, the Xinjiang-Tibet highway will no longer be considered as built illegally on Indian territory.
- Conclusion
This article has examined the competing claims to Aksai Chin through the framework of international territorial law rather than political rhetoric or strategic considerations. It has demonstrated that neither party possesses a conclusive treaty-based title to the disputed territory, thereby necessitating recourse to subsidiary principles governing the acquisition and proof of sovereignty. While India’s position rests predominantly upon the Johnson Line and historical assertions of title, these foundations are weakened by the absence of consistent official recognition prior to independence, the lack of communication of the claimed boundary to China, and the limited evidence of actual administration in the region. By contrast, although China’s claim likewise suffers from the absence of an express treaty, it is supported by a more coherent historical practice, greater continuity of administrative control, and conduct more readily capable of constituting legally relevant effectivités under international law.
The analysis does not suggest that the dispute is therefore conclusively resolved as a matter of law, nor that considerations of diplomacy, security, or political compromise have become irrelevant. It does, however, indicate that, viewed solely through the principles governing territorial sovereignty as developed in international jurisprudence, the legal position advanced by China in the western sector appears more persuasive than that of India. Whether this legal reality will ultimately translate into a negotiated settlement remains uncertain. Yet, as long as the parties continue to rely upon fundamentally incompatible historical narratives rather than mutually accepted legal principles, the western sector of the Sino-Indian boundary is likely to remain not merely a contested frontier, but an enduring illustration of the limits of history when detached from law.
Bibliography
Primary Sources
Official Documents
Letter from Prime Minister Jawaharlal Nehru to Prime Minister Zhou Enlai (26 September 1959).
Nehru J, Selected Works of Jawaharlal Nehru, Second Series, vol 60 (5 April–31 May 1960).
Prime Minister on Sino-Indian Relations: Vol I, Part I: 1961 and Part II: 1962 (External Publicity Division, Ministry of External Affairs, Government of India).
International Cases and Arbitral Awards
Clipperton Island (Mexico v France) (Award) (28 January 1931) 2 RIAA 1105.
Frontier Dispute (Burkina Faso/Mali) (Judgment) [1986] ICJ Rep 554.
Honduras Borders (Guatemala v Honduras) (Award) (23 January 1933) 2 RIAA 1303.
Island of Palmas (Netherlands v United States) (Award) (4 April 1928) 2 RIAA 829.
Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v Nigeria; Equatorial Guinea intervening) (Judgment) [2002] ICJ Rep 303.
Legal Status of Eastern Greenland (Norway v Denmark) (Judgment) PCIJ Rep Series A/B No 53 (1933).
Minquiers and Ecrehos (France/United Kingdom) (Judgment) [1953] ICJ Rep 47.
Sovereignty over Pedra Branca/Pulau Batu Puteh, Middle Rocks and South Ledge (Malaysia/Singapore) (Judgment) [2008] ICJ Rep 12.
Secondary Sources
Books
Bajpai KP and Mattoo A, The Peacock and the Dragon: India–China Relations in the 21st Century (Har-Anand Publications 2000).
Bhattacharya A, Journeys on the Silk Road Through Ages—Romance, Legend, Reality (Zorba Books 2017).
Bradnock RW, The Routledge Atlas of South Asian Affairs (Routledge 2015).
Brownlie I, Brownlie’s Principles of Public International Law (8th edition, Oxford University Press 2012).
Gupta K, The Hidden History of the Sino-Indian Frontier (Macmillan 1974).
Lamb A, The Sino-Indian Border in Ladakh (Australian National University Press 1973).
Lamb A, Kashmir: A Disputed Legacy, 1846–1990 (Roxford Books 1991).
Malone D, Mohan CR and Raghavan S (eds), The Oxford Handbook of Indian Foreign Policy (Oxford University Press 2015).
Oellers-Frahm K, Minnerop P, Schorkopf F, & Walter C (eds), World Court Digest 2001–2005 (Springer 2008).
Orton A, India’s Borderland Disputes: China, Pakistan, Bangladesh and Nepal (Epitome Books 2010).
Palit DK, War in High Himalaya: The Indian Army in Crisis, 1962 (Lancer International 1991).
Pan J, Toward a New Framework for Peaceful Settlement of China’s Territorial and Boundary Disputes (Martinus Nijhoff 2009).
Rao P, India’s Political Blunders Bleeding Its Borders (Blue Rose Publishers 2021).
Ray JK, India’s Foreign Relations, 1947–2007 (Routledge 2013).
Sali ML, India-China Border Dispute: A Case Study of the Eastern Sector (APH Publishing 1998).
Saran S, How India Sees the World: Kautilya to the 21st Century (Juggernaut Books 2017).
Saxena AK, Dividing Boundaries: Contours of Indo-China Conflict (Gaurav Book Center 2015).
Shah SK, India and China: The Battle between Soft and Hard Power (Vij Books India 2015).
Shankar V, Charting Global Transitions (Institute of Peace and Conflict Studies 2015).
Snedden C, Understanding Kashmir and Kashmiris (OUP 2015).
Van Eekelen W, Indian Foreign Policy and the Border Dispute with China: A New Look at Asian Relationships (Brill 2015).
Vengasseri I, 1962 Border War: Sino-Indian Territorial Disputes and Beyond (SAGE Publishing India 2020).
Journal Articles
Guruswamy M, ‘India-China Border Learning from History’ (2003) 38 Economic and Political Weekly 4101.
Karackattu JT, ‘India-China Border Dispute: Boundary-Making and Shaping of Material Realities from the Mid-Nineteenth to Mid-Twentieth Century’ (2017) Journal of the Royal Asiatic Society.
Liu Z, ‘Boundary Standoff and China-India Relations: A Chinese Scholar’s Perspective’ (2020) 6 China Quarterly of International Strategic Studies 223.
Masahiro M, ‘The “Critical Date” of the Takeshima Dispute’ (2014) 3 Review of Island Studies 28.
O’Keefe R, ‘Legal Title versus Effectivités: Prescription and the Promise and Problems of Private Law Analogies’ (2011) 13 International Community Law Review 147.
Prorok AK and Huth PK, ‘International Law and the Consolidation of Peace Following Territorial Changes’ (2015) 77 Journal of Politics 161.
Rossi C, ‘Interstitial Space and the High Himalayan Dispute between China and India’ (2021) 62 Harvard International Law Journal 429.
Sebastian N, ‘Intrusions and Violation of LAC in India–China Border’ (2020) 55 Economic and Political Weekly.
Zhang H and Li M, ‘Sino-Indian Border Disputes’ (2020) 181 Analysis 1.
Online Sources
MacDonald M, ‘The Sino-Indian Standoff and a Most Misunderstood Frontier’ (War on the Rocks, 15 July 2020) [https://warontherocks.com/the-sino-indian-standoff-and-a-most-misunderstood-frontier/](https://warontherocks.com/the-sino-indian-standoff-and-a-most-misunderstood-frontier/) accessed 29 June 2026.
Verma VS, ‘Sino-Indian Border Dispute at Aksai Chin: A Middle Path for Resolution’ (2010 [https://chinaindiaborderdispute.files.wordpress.com/2010/07/virendravermapaperborderdispute.pdf (https://chinaindiaborderdispute.files.wordpress.com/2010/07/virendravermapaperborderdispute.pdf) accessed 23 June 2026.
[1] Letter from Prime Minister Jawaharlal Nehru to Prime Minister Zhou Enlai (26 September 1959).
[2] J Nehru, Selected Works of Jawaharlal Nehru, Second Series, vol 60 (5 April–31 May 1960) 29.
[3] D Malone, CR Mohan & S Raghavan (eds), The Oxford Handbook of Indian Foreign Policy (OUP 2015) 58.
[4] H Zhang & M Li, ‘Sino-Indian Border Disputes’ 181 Analysis 1, 2-3; C Snedden, Understanding Kashmir and Kashmiris (OUP 2015) 121; A Bhattacharya, Journeys on the Silk Road Through Ages—Romance, Legend, Reality (Zorba Books 2017) 129; Z Liu, ‘Boundary Standoff and China-India Relations: A Chinese Scholar’s Perspective’ (2020) 6 CQISS 223, 227; S Hoffmann, India and the China Crisis (UCP 2018) 13.
[5] A Orton, India’s Borderland Disputes: China, Pakistan, Bangladesh and Nepal (Epitome Books 2010) 12; AK Saxena, Dividing Boundaries Contours of Indo-China Conflict (Gaurav Book Center 2015) 4; N Sebastian, ‘Intrusions and Violation of LAC in India–China Border’ (2020) 55 EPW 1, 23.
[6] Sebastian (n 5) 23; KP Bajpai & A Matto, The Peacock and the Dragon: India–China Relations in the 21st Century (Har–Anand Publications 2000) 200.
[7] Nehru (n 2) 29 (Nehru-Choi Talks II, April 20 from 5 p.m. to 7 p. m., 1959).
[8] C Rossi, ‘Interstitial Space and the High Himalayan Dispute between China and India’ (2021) 62 HILJ 429, 455.
[9] Ibid.
[10] I Vengasseri, 1962 Border War: Sino-Indian Territorial Disputes and Beyond (SAGE Publishing India 2020) 45; VS Verma, ‘Sino-Indian Border Dispute at Aksai Chin: A Middle Path For Resolution’ (2010) <https://chinaindiaborderdispute.files.wordpress.com/2010/07/virendravermapaperborderdispute.pdf> 8 [accessed 23-06-2026]; A Lamb, The Sino-Indian Border in Ladakh (Australian National University Press 1973) 8-9.
[11] Hoffmann (n 4) 13.
[12] Liu (n 4) 229; DK Palit, War in High Himalaya: The Indian Army in Crisis, 1962 (Lancer International 1991) 32.
[13] M Guruswamy, ‘India-China Border Learning from History’ (2003) 38 EPW 4101, 4102; P Rao, India’s Political Blunders Bleedings Its Borders (Blue Rose Publishers 2021) 78.
[14] A Lamb, Kashmir: A Disputed Legacy, 1846-1990 (Roxford Books 1991) xii; Saxena (n 5) 3; Orton (n 5) 10.
[15] Malone (n 3) 58; Orton (n 5) 11.
[16] JT Karackattu, ‘India-China Border Dispute: Boundary-Making and Shaping of Material Realities from the Mid-Nineteenth to Mid-Twentieth Century’ (2017) 1 JRAS 25, 28; S Saran, How India Sees the World: Kautilya to the 21st Century (Juggernaut Books 2017) 129.
[17] R O’Keefe, ‘Legal Title versus Effectivités: Prescription and the Promise and Problems of Private Law Analogies’ (2011) 13 ICLR 147, 147.
[18] M Masahiro, ‘The “Critical Date” of the Takeshima Dispute’ (2014) 3 RIS 28, 28-49
[19] P Minnerop et al, World Court Digest 2001 – 2005 (Springer Science & Business Media 2008) 281; I Brownlie, Brownlie’s Principles of Public International Law (8th edn, OUP 2012) 222.
[20] Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria; Equatorial Guinea intervening) (Judgment) [2002] ICJ Rep 2002, para 223.
[21] Sovereignty over Pedra Brance/Pulau Batu Puteh, Middle Rocks and South Ledge (Malaysia/Singapore), (Judgment) [2008] ICJ Rep 2008, 12.
[22] Honduras Borders (Guatemala v Honduras) (Award) (23 January 1933) 2 RIAA 1325.
[23] Island of Palmas (Netherlands v United States) (Award) (4 April 1928) 2 RIAA 829, 868.
[24] Clipperton Island (Mexico v France) (Award) (28 January 1931) 2 RIAA 1105; Legal Status of Eastern Greenland (Norway v Denmark) (Judgment) PCIJ Rep Series A/B No 53 (5 September 1933).
[25] Frontier Dispute (Burkina Faso/Mali) (Judgment) [1986] ICJ Rep 1986, para 63.
[26] Minquiers and Ecrehos (France/United Kingdom) (Judgment) [1953] ICJ Rep 1953, 47, 55.
[27] AK Prorok & PK Huth, ‘International Law and the Consolidation of Peace Following Territorial Changes’ (2015) 77 J Polit 161 164.
[28] Burkina Faso/Mali, para 63.
[29] M MacDonald, ‘The Sino-Indian Standoff and a Most Misunderstood Frontier’ (War on the Rocks, 15 July 2020) <https://warontherocks.com/the-sino-indian-standoff-and-a-most-misunderstood-frontier/> [accessed 29-06-2026]; W Van Eekelen, Indian Foreign Policy and the Border Dispute with China: A New Look at Asian Relationships (Brill 2015) 175.
[30] JK Ray, India’s Foreign Relations, 1947-2007 (Routledge 2013) 249; J Pan, Toward a New Framework for Peaceful Settlement of China’s Territorial and Boundary Disputes (Martinus Nijhoff Publishers 2009) 201-202.
[31] Lamb (n 10) 56; RW Bradnock, The Routledge Atlas of South Asian Affairs (Routledge 2015) 174.
[32] ML Sali, India-China Border Dispute: A Case Study of the Eastern Sector (APH Publishing 1998) 245.
[33] Prime Minister on Sino-Indian Relations: Vol I, Part I: 1961 and Part II: 1962 (External Publicity Division, Ministry of External Affairs, Government of India) 120, 148; Karackattu (n 16) 20 no 79.
[34] See e.g. K Gupta, The Hidden History of the Sino-Indian Frontier (Macmillan 1974) 53; Vengasseri (n 10) 127; See also SK Shah, India and China: The Battle between Soft and Hard Power (Vij Books India Pvt Ltd 2015) 276.
[35] Saxena (n 5) 281.
