Not every territory in the world is independent. The Chagos Archipelago is one example. But an agreement with the United Kingdom government is about to change all that. The Chagos Island is now set to return to the warm embrace of the nation of Mauritius, the rightful owner.
Located in the middle of the Indian Ocean, the Chagos Archipelago has been at the center of contention for many decades. Mauritius and the United Kingdom have clashed in multiple international courts. But a series of verdicts favoring Mauritius hasn’t resulted in any change.
Thankfully, the UK government, led by Prime Minister Sir Keir Starmer, has made a monumental U-turn. On May 22, 2025, he signed an agreement that would return the islands to their former owners. It is a 99-year deal that will cost the UK government at least £101 million every year.
Interestingly, the deal isn’t going to end the UK’s influence on the island altogether. The United States will also benefit from the agreement.
Here, we’d find out how much independence the deal would provide, how much the United States and the United Kingdom would benefit, and how Mauritius lost control of the territory. We’d also see how much it would cost the UK and why it finally agreed to let go of the islands.
What Is the UK and Mauritius Chagos Island Deal About?
According to Mauritian Prime Minister Navin Ramgoolam, the Chagos Island agreement has completed “the total process of decolonization.” Through the deal, the UK will forfeit its colonial control of the place. The territory will now be under the control of Mauritius after 60 years of British administration.
However, the UK will continue to use the Chagos Archipelago’s longest island, Diego Garcia. This use will be supported by a yearly rent of £101 million. The UK and the United States have since used the Diego Garcia island as a military base. Although military operations on the island will continue, the British military will only be tenants.
The lease agreement will last for 99 years, with an option to extend for an additional 40 years if both parties agree. According to the British Prime Minister, the members of the Five Eyes Alliance collectively decided to continue using the Diego Garcia island. These are the countries of the UK, the US, Australia, Canada, and New Zealand.
Additionally, the UK will make a total payment of £165 million per year for the first three years following the signing of the agreement. After that, Mauritius will receive £120 million from the 4th to the 13th year. Then, a further inflation-adjusted £120 million each year from year 14 to year 99.
This is in addition to a further £45 million every year for the funding of Mauritian development projects for the first 25 years. The agreement also sanctioned the setup of a £40 million trust fund to help the native inhabitants of the island.
In the end, the UK will have coughed up £3.4 billion. However, financial analysts have estimated the UK’s planned net spend at £30 billion, taking into account inflation and other factors.
Non-Financial Provisions
Aside from the use of Diego Garcia island as a military base, the agreement has some more significant non-financial provisions. These include resettlement plans for the Chagossians, who were displaced by the British when they took control of the island in 1965.
The deal allows Mauritius to implement a resettlement for the Chagossians except on the Diego Garcia island. This is because of the plan to continue using the island for joint UK and US military operations. The trust fund will serve the welfare of the resettled people.
Retaining Diego Garcia is crucial for the UK’s security. The military base on the island is the British government’s most important strategy in countering any hostile nation in the Middle East, Indo-Pacific, and Southern Asia.
Aside from other combat installations, the UK has built an electromagnetic spectrum satellite on the island. This is a communication system set up to counter enemy advances. But there’s more.
To protect the UK’s territorial security, the deal has also sanctioned the preservation of a buffer zone around the island. Mauritius can only build on this 25-mile buffer zone with permission from the UK.
Which Country Does the Chagos Islands belong to?
Before now, the UK has been, for several decades, in the custody of the island, which is about 5,799 miles away in the southeast direction. The island is 1,250 miles away from mainland Mauritius in the northeast direction and had no inhabitants until the 18th century.
Then, the French, who were the first to discover the islands, brought in slaves in 1793 and established plantations. However, in 1814, they gave the islands to the British, along with Mauritius. This was before Seychelles broke away.
In 1965, the British named the islands the “British Indian Ocean Territory.” By the time Mauritius gained independence in 1968, the UK had paid the country £3 million to lease the Chagos Islands. The U.S. had convinced the British to acquire the island for military purposes.
However, Mauritius has disagreed with the narrative that they voluntarily leased out the islands. They claimed that the UK forced them to lease the island as a condition for independence. Unverified historical accounts state that the UK forcibly displaced between 1,400 and 1,700 Chagossians from the islands.
To date, displaced Chagossians continue to live in Crawley, Sussex, and Manchester. Others moved to Mauritius and the Seychelles. They’ve been itching to return to their homeland, and many have filed lawsuits against the UK in international courts contesting its occupation of the Archipelago.
Why Has the UK Decided to Return the Islands?
The UK decided to end its control over the Chagos Archipelago due to mounting pressure. It also wanted to set a good example to gain respect and followership on the global scene.
Pressure became overwhelming on February 25, 2019, after the International Court of Justice (ICJ) ruled that the UK’s continuous occupation of the Chagos Islands was unlawful. The ICJ decided 13-1 that the UK’s seizure of the islands violated Mauritius’ rights.
It also ruled that the “lease” of the land was done under duress and colonial pressure. In addition, it called on the UK to transfer control of the island to Mauritius as soon as possible.
The UK defied the ruling, stating that the court’s verdict was only advisory. However, the ruling led to subsequent decisions in favor of Mauritius. One example was the United Nations General Assembly resolution of May 2019, which called on the UK to return the islands in six months.
Due to these mounting calls, the UK government decided to strike an agreement to withdraw its control of the islands. Interestingly, the signing of the Chagos agreement was almost hampered by a lawsuit from two Chagossian women.
Bertrice Pompe and Bernadette Dugasse filed a suit before the UK High Court to stop the agreement. They stated that the rights of the Chagossians were violated, seeing that they weren’t involved in the negotiations. However, the UK High Court dismissed the suit and cleared the way for the deal to be signed.
Plans to Reach an Agreement Have Stalled for Years
For years, plans to strike a deal have failed at the negotiation table. Former UK Foreign Secretary James Cleverly raised hopes of an imminent agreement in 2022. In a press statement, he disclosed plans by the then-Prime Minister, Liz Truss, to visit Mauritius by early 2023.
True to his words, Truss met with Mauritius officials in New York in October 2022. However, neither party was able to reach a compromise.
This failure was one of several unfruitful meetings between the two parties. Current Defense Secretary, John Healey, didn’t fail to mention this in his defense of Keir Starmer’s competence in steering the ship of the British government.
Healey stated that Starmer reached the agreement after about a dozen rounds of talks hit brick walls. He further praised his Labour Party-controlled government for the breakthrough, while also highlighting how the agreement had brought more benefits to the UK.
In his own words, he stated that the Labour Party ministers “toughened the terms and the protections and the control that Britain can exercise through this treaty.” Starmer has also been excited about the deal.
The UK’s Government Has Patted Themselves on Their Backs
In a news conference, the Prime Minister highlighted some of the proudest aspects of the deal. One of them was the ability to preserve the military base in Diego Garcia. He described the base as being of “utmost significance to Britain.”
Starmer also defended the decision to reach a deal and hand over the islands. “If we did not agree on this deal, the legal situation would mean that we would not be able to prevent China or any other nation from setting up their bases on the outer islands or carrying out joint exercises near our base,” he stated.
The United States government, which has partnered with the UK in operating the base, has also commented on the agreement. Secretary of State Marco Rubio said the deal “secures the long-term, stable and effective operation of the joint US-UK military facility at Diego Garcia, which is critical to regional and global security.”
The Deal Has Met Stiff Criticism
Interestingly, not every Briton is excited about the agreement. Keir Starmer’s efforts have been criticized by the Conservative Party, whose leader, Kemi Badenoch, has described the deal as a dangerous one.
She stated that the deal would not benefit the UK but instead harm it. Badenoch noted that the agreement makes Britain “more exposed to China, and ignores the will of the Chagossian people.”
Another notable voice against the agreement is the Reform UK leader, Nigel Farage. He echoed Kemi Badenoch’s views, stating that the deal was useless and placed the UK at the mercy of its Asian foes, such as China.
They argued that having Mauritius, which has been an ally of China, as a neighbour could pose a threat to Britain. Over the years, Mauritius has forged a solid partnership with China.
The world’s power has, in return, invested in the nation’s infrastructure. There is also a free trade agreement between them, which has been in force since 2019. Critics say that this relationship can lead to Chinese influence over the Chagos Islands.
They have pointed to the possibility of Mauritius granting China access to specific sections of the island. This, they say, could place the UK at the mercy of the Asian giant.
However, Keir Starmer is confident that the deal is threat-proof. Is it? Well, only time will tell.
