Context: Britain has agreed to transfer sovereignty of the Chagos Islands, a group of over 60 islands in the Indian Ocean, to Mauritius. 

• This deal ensures the future of the UK-US military base on Diego Garcia, the largest island, with its status now undisputed and legally secure for the first time in over 50 years. 

• India welcomed the agreement, seeing it as completing the decolonization of Mauritius.

Chagos Islands

Geographical location

• The Chagos Archipelago is located in the central Indian Ocean, about 500 kilometers south of the Maldives and roughly 1,600 kilometers southwest of India.

• The Chagos archipelago comprises of 58 islands, with Diego Garcia being the largest and most significant.

Colonial history of Chagos 

• According to a report, the Chagos Islands were discovered by Portuguese navigators in the 16th century, who mapped and named some of them. 

• The Dutch explored the islands next but did not settle there. 

• The islands later came under French control, along with Mauritius and Réunion, and the French gave additional names to the islands. 

• They brought enslaved workers from Madagascar and Mozambique, followed by laborers from southern India, to work on coconut plantations. 

• After Napoleon's defeat, Britain took control of both Chagos and Mauritius.

• In 1814, France ceded the islands to the British.

Significance of Chagos

• Geostrategic Location: The archipelago's location in the central Indian Ocean makes it strategically valuable for monitoring major shipping lanes, ensuring security in the region, and projecting military power across a wide area.

• UK-US Military Base: Diego Garcia, the largest island, hosts a major UK-US military base, which is crucial for operations in the Indian Ocean and surrounding regions. 

• It serves as a logistics, surveillance, and intelligence hub for both the UK and the US, playing a key role in military operations in the Middle East, Africa, and South Asia.

• Environmental and Biodiversity Significance: The Chagos Archipelago is home to one of the largest coral atolls and is rich in marine biodiversity. 

• Its pristine environment has made it important for scientific research and conservation efforts.

Chagos Islands dispute

• UK Declares Chagos Islands as Overseas Territory

• In November 1965, the UK declared the Chagos Islands as an overseas territory. 

• After Mauritius gained independence in 1968, the UK refused to return the islands.

• In 1965, the UK constituted the British Indian Ocean Territory (BIOT), of which the Chagos Islands were a central part. 

• Chagos was attached to Mauritius, another British colony in the Indian Ocean, for administrative purposes.

• When Mauritius gained independence in 1968, Chagos remained with Britain. 

• The UK government gave the newly-independent country a grant of 3 million pounds over the “detachment” of the Chagos archipelago.

• Strategic Military Use of Diego Garcia

• Diego Garcia became the site of a major UK-US military base, which played a crucial role in US-led operations in Afghanistan and Iraq in the 2000s. 

• Following the September 11, 2001 attacks, the base also served as a CIA interrogation site.

• Mauritius’ Proposal and UK’s Rejection

• After gaining independence, Mauritius proposed allowing the UK to lease the islands to the US for defense purposes in exchange for an increased US quota for sugar imports, which would boost Mauritius' economy. 

• The UK rejected the proposal, claiming the US could not be involved in any treaty, despite benefiting from the islands.

• Forced Depopulation of Chagossians

• Between 1968 and 1973, the UK and US forcibly removed the native Chagossians to make way for the military base. 

• The UK denied the inhabitants' connection to the islands, dismissing claims of human rights violations.

• Legal Action by Mauritius

• In 2015, Mauritius initiated legal proceedings against the UK at the Permanent Court of Arbitration in The Hague, challenging the UK's sovereignty claims and addressing the forced removal of the Chagossians. 

• The UK resisted, insisting that the issue should remain a bilateral matter.

• Permanent Court of Arbitration’s 2015 Ruling Against the UK

• In 2015, the Permanent Court of Arbitration ruled that the UK had violated Mauritius’ rights under the United Nations Convention on the Law of the Sea (UNCLOS). 

• The court found that the UK had ulterior motives when it created a Marine Protected Area (MPA) around the Chagos Islands in 2010, intentionally preventing the return of the Chagossians. 

• The ruling highlighted that British and American defense interests were prioritized over Mauritius' rights, and the UK's actions were deemed a violation of good faith.

• UN General Assembly Vote in 2017

• In June 2017, the UNGA voted on Mauritius’ resolution to seek an advisory opinion on the Chagos Islands from the International Court of Justice (ICJ). 

• The result reflected global opposition to colonial legacies and suggested that the UN was unlikely to endorse continued colonial control.

• International Court of Justice (ICJ) Ruling in 2019

• In February 2019, ICJ ordered the UK to return the Chagos Islands to Mauritius as rapidly as possible. 

• Mauritius argued that it had been coerced into giving up the islands during colonial rule, in violation of UN resolution 1514, which prohibited the breakup of colonies before independence. 

• The UK claimed that the ICJ had no jurisdiction over the matter. 

• UK hands over Chagos Islands to Mauritius

About the treaty

• The UK and Mauritius reached an agreement where the UK ceded its claims over the Chagos Archipelago. 

• The agreement allows the UK to retain sovereign rights over Diego Garcia, where a joint UK-US military base will remain operational for an initial period of 99 years.

• Mauritius is now allowed to implement a resettlement program on the islands, except for Diego Garcia. 

• Additionally, the UK has pledged to create a trust fund to benefit the displaced Chagossians.

Role of India

• India has maintained steadfast support to Mauritius’ claims over the Chagos Islands. 

• It voted in favour of the island country at the UNGA in 2019. 

• In recent years, India has attempted to deepen its ties with Mauritius amidst China’s ever-increasing assertiveness in the Indian Ocean. 

• Earlier this year, an India-built airstrip and a jetty was inaugurated at Agaléga, a two-island dependency of Mauritius in the Western Indian Ocean.

Significance of Treaty

• Addressing colonial legacy: Ends a long-standing dispute over last British colony in Africa.

• Regional Security Dynamics: As Mauritius may seek to balance its relations with major powers.

• Security Importance: Diego Garcia base allows US to monitor Malacca Strait, crucial for global trade, and maintain its presence in IOR.

• Compliance with International Law: Handing over island is aligned with judgment of International Court of Justice In 2019 & UNGA resolution in 2019.

• India supported Mauritius' claim by voting in its favor at UNGA in 2019

• It was in line with India’s “principled stand on decolonization and support for sovereignty and territorial integrity of nations”.