The Chagos Islands deal just exploded back into the spotlight. I can confirm that fresh political fire on both sides of the Atlantic has turned a careful decolonization settlement into a hard security fight. The trigger was sharp criticism today from Donald Trump, paired with new backlash inside the UK. The core questions are now plain. What exactly did the UK and Mauritius agree to, what rights do Chagossians get, and what happens to the U.S.–UK base on Diego Garcia?
What changed today
Trump called the UK’s agreement to transfer sovereignty to Mauritius, while leasing Diego Garcia, a strategic mistake. His attack aims at the heart of the pact, the base that anchors U.S.–UK power across the Indian Ocean. In Westminster, the politics are also moving. Conservative MP Andrew Rosindell’s defection to Reform UK over this deal adds real pressure on the government’s security case.
Here is the point. The treaty was built to close a long legal dispute while keeping the base running. Trump’s move reframes it. It turns a decolonization fix into a test of Western resolve.
The treaty transfers sovereignty to Mauritius, keeps Diego Garcia for U.S.–UK use under a 99-year UK lease, and allows a 40-year extension.
What the treaty actually does
I have reviewed the key terms and the legal logic is clear. The UK recognized Mauritius as the sovereign over the Chagos Islands. In return, Mauritius granted the UK a 99-year lease for Diego Garcia, with an option to extend by 40 years. The UK will pay roughly 101 million pounds per year. Operational control of the base remains with the U.S. and UK under existing defense arrangements, subject to the lease.
The agreement builds guardrails to calm security and sovereignty fears. Mauritius holds a veto on commercial development that could threaten the base. There is a permanent buffer zone around Diego Garcia. No foreign military other than the U.S. and UK can deploy in the islands.
- 99-year lease to the UK, with a 40-year extension option
- Annual payment near 101 million pounds
- Mauritius development veto and a base buffer zone
- Ban on any other foreign military presence
This structure keeps the base steady, but it also inserts Mauritius into the security equation. That split, decolonization plus defense, is the new normal.
The law, and those still left out
The legal backdrop matters. In 2019, the International Court of Justice and the UN General Assembly told the UK to end its administration and return the territory to Mauritius. The 2025 treaty answers that call, at least on paper. It recognizes Mauritian sovereignty, which moves the UK into a tenant role on Diego Garcia, not the owner.
What about Chagossians, the people who were expelled to make way for the base? The deal sets up a trust fund and a resettlement path in outer islands. It does not allow return to Diego Garcia. That is the fault line now driving litigation. Chagossian claimants argue they were not properly consulted. They say the plan fails on rights of abode and fair resettlement. Courts in the UK have allowed steps toward review, and more claims are coming.
Resettlement excludes Diego Garcia. The base island stays closed to civilian return under the lease.
Security stakes and the road ahead
Diego Garcia is central to operations across the Indo-Pacific and the Middle East. Bombers, submarines, and surveillance flights rely on it. The lease protects that footprint, but it also creates shared management. Mauritius will have a real say on development and environmental rules. Supporters call this a stable balance. Critics, like Trump, say it hands leverage to a small state and invites pressure from rivals.
The next moves now matter more than the headlines.
- Mauritius must finalize domestic laws to run the outer islands.
- The UK and Mauritius will seat a joint body to manage the buffer zone and permits.
- London must lock in the trust fund rules and publish a clear resettlement scheme.
- UK courts will decide if consultations and rights of abode met legal standards.
Any slip here, on consultation or transparency, will land back in court or in Parliament. That would slow resettlement, and it could unsettle base planning.
What citizens should watch
For Chagossians, this is about rights, voice, and place. The key tests are simple. Does the trust fund deliver, is there a fair path to live and work on the outer islands, and do families have a seat at the table. For UK citizens, the focus is oversight. The lease costs real money and carries risks. Parliament should demand regular reporting on the trust fund, environmental compliance, and any limits the veto places on base operations.
Chagossian community groups should press for written timelines, published consultation notes, and seats on the trust fund board. Paper trails protect rights.
This story is not a footnote to empire. It is a live case of how we end colonial chapters without opening security gaps. The treaty answers the ICJ and keeps Diego Garcia running. Trump’s attack, and the UK political split, test whether that balance can hold. The law has cleared a path. Now policy and people must walk it, step by step, without leaving anyone behind.
