Context: 

Britain and Mauritius are finalizing a deal to transfer sovereignty over the Chagos Islands, a disputed U.K. territory located in the Indian Ocean.

Key points of Agreement

• The plan to hand over control of the Chagos Islands, officially known as the British Indian Ocean Territory, was announced in October 2024.
• The proposed agreement would allow Mauritius to gain sovereignty over the Chagos Islands while permitting the US and UK to continue operating a military base on one of the islands.
• The UK plans to lease Diego Garcia, the largest island of the Chagos Archipelago, for 99 years, with a potential extension of 40 years.
• Once the treaty is signed, it will be presented to both houses of the UK Parliament for scrutiny and ratification.
• The draft agreement includes provisions for a resettlement fund to help displaced Chagossians return to the islands, excluding Diego Garcia. However, details of the resettlement plan remain unclear.

About the Chagos Archipelago

Geography: 

The Chagos Archipelago, comprises of 58 islands, that lies roughly 500 km to the south of the Maldives archipelago in the Indian Ocean. 

• It is located about 1,000 miles (1,600 km) south of the southern tip of the Indian subcontinent.

Despite its small land area of 56.1 sq km, however including the lagoons within its atolls, however, Chagos has a total area of more than 15,000 sq km. 

The Great Chagos Bank, the world’s largest atoll, spans 12,642 sq km. (An atoll is a ring-shaped coral reef, island, or series of islets, which surrounds a body of water called a lagoon)

It constitutes a semicircular group, open to the east, comprising the Salomon Islands, Peros Banhos atoll, Nelsons Island, the Three Brothers Islands, the Eagle Islands, Danger Island, the Egmont Islands, and Diego Garcia.

Historical Background: 

• The Portuguese visited and mapped out Chagos in the 16th century, and used the islands as a stopover in voyages around the Cape of Good Hope to India. 
• But it was only in the 18th century that the first permanent settlements emerged on the islands.
• France became the first European power to officially plant its flag on Chagos, when it claimed the Peros Banhos island in 1744. 
• The French had earlier set up Indian Ocean colonies in Île Bourbon (now Réunion) in 1665, Isle de France (now Mauritius) in 1715, and the Seychelles in 1744.
• In 1814, under the Treaty of Paris, France ceded Mauritius, including the Chagos Archipelago, to the British.
• After Britain abolished slavery in its colonies in 1833, indentured labour from India and Malaya was brought to the plantations.
• The Chagossian population today traces its origins to freed African slaves, and the Indian and Malayan labourers who arrived in the 18th and 19th centuries.

The British Indian Ocean Territory (BIOT)

In the 1950s, the US Navy identified Diego Garcia for establishing a military base in the Indian Ocean. The US initiated secret talks with the UK in 1960

In 1965, the UK separated the Chagos Islands from Mauritius (gained independence in 1968) to create the British Indian Ocean Territory (BIOT).

• The BIOT was meant to provide the British (and by extension their Cold War allies, the Americans) with an overseas base in the Indian Ocean.

In 1966, the UK and the US signed a secret agreement to establish a military base in Diego Garcia which became fully operational in 1986.

About the Diego Garcia

• A coral atoll, the largest and southernmost member of the Chagos Archipelago. It is located 7 degrees south of the equator.
• It consists of a V-shaped sand-fringed cay about 15 miles (24 km) in length with a maximum width of about 7 miles (11 km); its lagoon is open at the north end.

Strategic Importance of Diego Garcia:

• Diego Garcia has served as a pivotal U.S. military base since the early 1970s in the Indian Ocean, facilitating operations across multiple conflict zones, including the Gulf and South Asia.
• Through legal measures (the 1971 BIOT Immigration Ordinance and 2004 Orders in Council), it became a criminal offence for anyone without military clearance to be on the islands without a permit.
• Its strategic location allows for monitoring key maritime routes, which is particularly vital for U.S. interests amid rising tensions with China and other regional powers. 
• Numerous air operations were launched from Diego Garcia during the Persian Gulf War (1990–91), the U.S.-led strikes on Afghanistan (2001), and the initial phase (2003) of the Iraq War along with military operations in Libya.

India’s Stand:

• It has supported Mauritius’s claim for sovereignty over Chagos, in line with its principled stand on decolonization and support for the sovereignty and territorial integrity of nations. 
• India has a strong defense partnership with Mauritius, including construction of an Indian Navy base at Mauritius’ North Agalega Island, giving it a strong foothold in the central Indian Ocean.

Important Timeline of the Chagos Islands:

1783: The first inhabitants arrived as Enslaved Africans on the Chagos Islands to work on French coconut plantations. Later, indentured Indians joined after slave emancipation.

1814: Britain takes possession of the Chagos Islands from France.

1965: Britain detached the Chagos Islands from Mauritius to create the BIOT. 

• The UK and US agreed to establish a military base on Diego Garcia.

1968: Mauritius gains independence, but Chagos remains with Britain.

1967-1973: The entire Chagos population was forcibly relocated to Mauritius and Seychelles. 

• Human Rights Watch declares this a "crime against humanity."

2015: Mauritius filed a case against the UK at the Permanent Court of Arbitration (PCA) in the Hague

• The UK tried blocking the case, claiming the bilateral issue
• The court ruled that the UK violated Mauritius' rights and UN maritime law.

2019: The UN’s highest International Court of Justice (ICJ) rules British occupation illegal and orders the UK to hand it back to Mauritius.

• The UN General Assembly passes a motion condemning Britain’s occupation of the islands. 
• The UN demanded that Britain withdraw within six months, but the UK refused.

2021: UN maritime court rejects the UK's sovereignty claim.

2024: The UK agrees to transfer Chagos to Mauritius, retaining a joint US military base on Diego Garcia.