Overcoming the Diego Garcia Stalemate


During his 2017 visit to India as British foreign secretary, Boris Johnson failed to achieve a key diplomatic goal. Johnson was unable to convince India’s government to restrain its ally Mauritius from launching a diplomatic offensive against Britain over sovereignty of the Chagos Archipelago. Among its islands, Johnson and the U.K. government were most concerned about Diego Garcia, which is leased to the United States as a base for significant military and intelligence capabilities. India stood with Mauritius during all the diplomatic episodes that followed, including at the U.N. General Assembly and the International Court of Justice. The international court’s opinion on the matter was unfavorable to the United Kingdom and the U.N. General Assembly followed it by calling for a swift end to U.K. control of the islands.

Some believe Mauritius’ diplomatic successes were a “pyrrhic victory” because, if transfer of sovereignty leads to a reduction in American forces on Diego Garcia, it would upset the military balance that those forces uphold in the western Indian Ocean. Although Mauritius wishes to gain sovereignty over the Chagos Archipelago, its government, and that of its diplomatic supporter India, favor an American military presence there. The British, American, and Indian governments are actively aligning elsewhere in the Indo-Pacific region to uphold a rules-based order against China’s government. In the case of the Chagos Archipelago, they, along with Mauritius, compete due to mutually irreconcilable interests, which has led to a stalemate over sovereignty that seemingly assails international law and normative concerns.



Breaking that stalemate requires finding a proposal that can satisfy the interests of both Britain and Mauritius, as well as the interests of the other parties — the United States and India. A solution to the sovereignty dispute that leaves everyone better off could be devised: It would entail joint management of the Chagos Archipelago by Britain and Mauritius, without prejudicing their sovereignty claims. Such an arrangement would ensure American access to military facilities on Diego Garcia without imposing additional international law constraints, while the U.K. and Mauritian governments can jointly administer non-military issues such as fishing licenses and create a revenue sharing arrangement.

The U.S. military’s lease of Diego Garcia from the United Kingdom runs until 2036. Rather than wait for the sovereignty dispute to intensify at the time of those negotiations, the United Kingdom and Mauritius should consider implementing co-management as a stopgap solution, and the American and Indian governments should encourage them to do so.

The Disputants: Mauritius and the United Kingdom

Britain and Mauritius have been locked in a dispute over the Chagos Archipelago for decades. In 1965, the U.K. government excised the islands from Mauritius while granting the latter its independence. For the archipelago, Britain paid 3 million pounds to Mauritius and formed the British Indian Ocean Territory, from which it leased Diego Garcia to the United States. Governments in London repeatedly promised to “revert” the possession of the islands to Mauritius when the United Kingdom no longer required them for defense purposes, which not only sowed seeds of hope in Mauritius but also tacitly recognized the country’s sovereignty over the islands. However, the occasion for returning the islands to Mauritius never arose.

For Mauritian leaders, the benefits of sovereignty would include political glory and fiscal bounty. While Mauritian political leaders frequently raise the Chagossians’ right to domicile, Mauritius’ envoy to the United Nations has stated that as and when Mauritius regains sovereignty, Chagossians would be rehabilitated to three nearby islands, at least 100 miles away from Diego Garcia. That would be contrary to most Chagossians’ wishes of returning to Diego Garcia itself.

The Chagos dispute is a political hot potato in Mauritius, especially between the Ramgoolam and Jugnauth families, two political dynasties that have alternated in power since 1968. Sir Seewoosagur Ramgoolam, who oversaw Mauritius’ independence from the United Kingdom, has been accused of betrayal and venality as some of the rehabilitation fund offered by London never reached its intended beneficiaries. For his son Navin, a former prime minister, trying to resolve the Chagos dispute was about redressing his father’s legacy of incomplete decolonization. For their political rivals — the late Anerood Jugnauth, another former prime minister, and his son Pravind, who has been prime minister since 2017 — the Chagos dispute is a way to engage in one-upmanship over the Ramgoolams.

For Mauritian political leaders, attempting to regain control of the archipelago is also about cashing in on Mauritius’ coveted strategic position. Compared to the Red Sea littorals and countries on the East African coastline — some of which earn millions of dollars by leasing strategic real estate — Mauritius is at a notional loss. For instance, military bases provide a significant revenue stream for Djibouti: The country annually receives $70 million from the United States, $36 million from France, $20 million from China, $2.6 million from Italy, and undisclosed amounts from Japan and Saudi Arabia. On top of that, Djibouti gains economic benefits in ancillary sectors that support thousands of troops. By comparison, the military outpost of Diego Garcia generates zero revenue for Mauritius. In addition to receiving no rent for it, Mauritius also loses revenue because its fishing rights remain curtailed after London proclaimed the Chagos Archipelago and its surrounding area to be a “marine protected area.”

The United Kingdom has strategic reasons for maintaining control of the archipelago, despite the unfavorable advisory opinion from the International Court of Justice, losing the U.N. General Assembly vote over the opinion, and failing to prove its sovereignty over the islands in an International Tribunal for the Law of the Seas hearing between Mauritius and the Maldives. While Diego Garcia is technically a joint facility, British troops are not stationed there permanently. But, by the British government’s own admission, the presence of British forces is “a visible demonstration of United Kingdom sovereignty of the archipelago.”

As a former shadow of its colonial self, the U.K. government can point to Diego Garcia as one important way that it contributes to American military and intelligence capabilities, as well as to those of the “Five Eyes” intelligence alliance more broadly. With the changing geopolitical context, and London’s clear tilt toward the Indo-Pacific region in its recent strategic review, Indian Ocean territories give Britain more “skin in the game” than a waning naval power otherwise would have. Motivated by these interests and aware of America’s unwavering support, the British government remains steadfast in the face of Mauritius’ incessant diplomatic campaign. Hence, in all diplomatic parleys, the British pass the buck by informing Mauritians that it is “up to the Americans.”

The Other Interested Parties: The United States and India

Both the United States and India also have interests at stake in the sovereignty dispute between Mauritius and the United Kingdom.

The American government has overlooked reputational costs and Mauritius’ repeated offers, both in public and private, to lease the base back to the United States for 99 years in exchange for supporting its case for sovereignty. Like British policymakers, American officials see strategic reasons for maintaining the status quo. If Mauritius had sovereignty over the islands, the African Nuclear-Weapon-Free Zone Treaty — also known as the Pelindaba Treaty — would apply to Diego Garcia as a Mauritian territory. As a party to the treaty, Mauritius cannot “station” nuclear explosives on its territory, including those carried by foreign ships or aircraft. This could present an obstacle to deployments of U.S. bombers and visits by American submarines, due to the U.S. policy of neither confirming nor denying the presence of nuclear weapons aboard aircraft, surface ships, and attack submarines.

Some claim that Mauritius can avoid such restrictions through a contrived interpretation of the treaty, due to ambiguity in its text about port-call timing. However, Mauritian leaders’ past behavior, including calling for International Atomic Energy Agency inspection of Diego Garcia and lodging diplomatic protests against the passage of submarine tender USS Emory S. Land, does not square with such optimism. The Obama administration signed the Pelindaba Treaty’s additional protocols for the five Nuclear Weapons States, which would require them to comply with treaty obligations such as not hosting nuclear weapons on a signatory state’s territory. However, the U.S. Senate never ratified those additional protocols.

The United Kingdom did sign those same protocols, but it made an explicit exception for the Chagos Archipelago, as it has done for at least eight other environmental and human rights treaties. Britain’s decision to make those exceptions relieves the United States from numerous international law obligations in relation to Diego Garcia. Under Mauritian sovereignty, the U.S. military base would become subject to many international conventions and treaties, imposing additional legal constraints on U.S. military and intelligence activities. Hence, Mauritian officials’ public offer that, in the event of Mauritius’ sovereignty over Diego Garcia, they “would permit the unhindered operation of the defence facility, in accordance with international law,” seems unlikely to persuade American policymakers.

Mauritian sovereignty over Diego Garcia would also leave the United States facing increases in rental costs. The United States leases Diego Garcia from the United Kingdom for free and derives considerable strategic benefits from the island, using it as a logistical hub, as a launchpad for air operations in surrounding theaters, and as a reconnaissance station. Host nations know that they can charge more in rental costs for bases with greater strategic relevance. Djibouti was able to more than double its ask of the United States for use of Camp Lemonnier, from $30 million to $70 million annually. American negotiators fear that host nations can increase their demands from time to time. However, the cost factor would remain secondary amid the vast American defense budget and compared to the significant utility of the base. Finally, as U.S. and U.K. interests coincide, American policymakers have no reason to snub a vital ally like the United Kingdom by not supporting it.

For India, during the Cold War, taking a position on Chagos meant choosing between the benefits of U.S. presence in the Indian Ocean — to check China — and its principled stance on decolonization. Presently, the Indian government seems to approach the issue more instrumentally, despite continuing to clutch to Cold War-era tropes publicly.

As officials of a rising power, Indian policymakers see certain countries, including Mauritius, as falling within its regional sphere of influence. New Delhi lends those countries moral and material support and Indian officials disapprove of major powers’ intrusion. In the Maldives, for example, Indian policymakers neither welcome a U.S. military presence nor a Chinese one. Hence, Indian officials only begrudgingly accepted the American military toehold in the Maldives, despite the balance it provides against China’s intended militarization of the Hambantota Port, a few hundred miles away in Sri Lanka. Some claim that New Delhi actively scuttled direct defense cooperation between the United States and the Maldives in 2014, indicating Indian policymakers’ reluctance to allow major powers to engage states that fall within what they see as India’s sphere of influence.

Although the official line is that India does not want to micromanage the Chagos affair, a section of Indian officials believes that, in relation to Diego Garcia, the United States should seek Indian assistance in encouraging a long-term solution to the dispute.

For its part, Mauritius has always looked to India for support for its international endeavors, including its recent efforts to exit the global financial watchdog’s gray list. U.N. insiders believe that Mauritius would never have been able to pull off its diplomatic victories against the United Kingdom in the General Assembly without India drumming up support. For Indian policymakers, not supporting Mauritius risks leaving it in search of another patron (i.e., China) but it also would mean losing a crucial African ally that is strategically positioned in the Indian Ocean. Hence, Indian officials treaded cautiously. Although India voted with Mauritius at the General Assembly over the Chagos dispute, it refrained from co-sponsoring the resolution. Similarly, India submitted a response to the International Court of Justice in favor of Mauritius after much deliberation, but some in Mauritius believed it to be tepid.

As interested parties to the dispute, India and the United States could, in theory, help Mauritius and the United Kingdom try to resolve their deadlock. They have, as yet, been unable to do so, even if their long-term interests to hedge against China align. The United States wants India’s help to silence Mauritius until 2036, when the lease for the Diego Garcia base opens for negotiations. India eyes the potential to deepen its political footprint in Mauritius, and to create leverage with the United States, by resolving the issue permanently.

American policymakers might have questions about the true degree of influence Indian policymakers enjoy with their counterparts in Mauritius. Such doubts were likely fueled by the fact that China made inroads into Mauritius with a trade agreement before India achieved one, while India’s development of infrastructure on Mauritius’ Agalega Island precipitated protests in the country. However, any American fears in that regard are misplaced. Mauritius, which fancies itself as the “Singapore of Africa,” wants to follow Singapore’s dehyphenation of economic and security policy — openly embracing China for trade while maintaining close-knit security collaboration with the United States and India. Similarly, New Delhi’s partnership is valued across party lines in Mauritius, and officials repeatedly underscore that they would not do anything that hurts Indian interests. Second, despite America’s readiness to invest in India’s rise in the Indian Ocean region, it seems the United States falls short in allowing India to build its own geostrategic orbit on which America might have to rely for its needs. This deficit upsets Indian diplomats and strategic thinkers, but at a moment when U.S. heft is needed the most against China, expressing a grudge is not a choice.

Toward a New Equilibrium: Joint Management of the Archipelago

The lack of convergence in the interests of Mauritius, the United Kingdom, the United States, and India has produced a stalemate over the status of the Chagos Archipelago. If Mauritius wants to resolve the issue, it should forge a new equilibrium that is a win-win for all. To start with, Mauritian policymakers need to continue assuring that they remain committed to American presence. Any signals of a pro-China tilt will hurt, not help, their cause. Quiet diplomacy might also yield better results than public acrimony. So far, it has not done so because, in public, Mauritius and the United Kingdom have tended to adopt maximalist positions. Additionally, to achieve success, Mauritian officials would likely benefit from Indian support during these negotiations. By having that, Mauritius is more likely to get the U.S. government to engage on this issue at a senior level.

Until the Diego Garcia base is up for renegotiation in 2036, Mauritius can ask for joint Mauritian-U.K. management of the archipelago — without giving up on the ultimate sovereignty dispute — while placing a reasonable price tag on the base. Mauritius was more than happy with a similar arrangement with the French government for the disputed Tromelin Island in 2010, a deal which the French parliament never ratified. In return, the United Kingdom can reduce the size of the marine protection area, ending it for northern parts of the archipelago, while allowing fishing rights to Mauritians. As part of joint management, the U.K.-appointed administrator could share authority with a Mauritian representative on issues that do not impact military matters. For instance, fishing licenses in newly permitted waters could be jointly issued with a revenue sharing arrangement established.

Such a deal would leave everyone better off. Mauritian leaders can claim diplomatic victory and their country would get compensated. The United Kingdom could continue force projection and the U.S. government would neither need to worry about additional international legal constraints nor upset an ally. India would cement its status in the region, without this entire issue becoming an international embarrassment for the parties involved.

If Mauritius proposes joint management of the archipelago, and is able to gain the support of the British and Indian governments, then American policymakers should respond constructively. If they do not, they would miss an opportunity to prove to the world that the U.S. government is as serious about international rules as it preaches to Beijing.



Chirayu Thakkar is a visiting fellow with the Stimson Center and a doctoral candidate in international relations at the National University of Singapore. His research focuses on the intersection of Indian multilateralism and strategic imperatives.

Correction: An earlier version of this article incorrectly stated that the United Kingdom extensively used the military facility on Diego Garcia during the Falklands War. In actual fact, the United Kingdom extensively used Ascension Island, part of a British Overseas Territory in the southern Atlantic Ocean, for logistical purposes during the Falklands War.

Image: U.S. Air Force