1965 – Britain separates the Chagos Archipelago from Mauritius, evicts up to 2,000 residents in the 1960s‑70s, later uses the islands for clandestine rendition flights in 2008, establishing the strategic base that underpins later disputes [6].

May 2025 – The United Kingdom and Mauritius sign a treaty that transfers sovereignty over the Chagos Islands to Mauritius while securing a 99‑year lease of Diego Garcia to the UK and US, with an average annual payment of £101 million and a net cost of £3.4 billion to Britain [5][11].

May 2025 – The United States publicly welcomes the UK‑Mauritius agreement, with Secretary of State Marco Rubio stating that the deal “secures a long‑term, stable and effective operation” at Diego Garcia, reinforcing the base’s role in regional security [5][11].

Jan 20, 2026 – President Donald Trump posts on Truth Social that the Chagos handover is “great stupidity” and “total weakness,” warning that China and Russia will notice, and he ties the criticism to his broader push to acquire Greenland for U.S. security [3][5][9][10][11].

Jan 20, 2026 – The British government counters that the agreement does not compromise national security, emphasizes continued U.S. support, and moves a parliamentary bill to embed the treaty into law, with the House of Commons passing it while the Lords approve it with regret, sending it back for further debate [3][10].

Jan 20, 2026 – Ahead of the Davos forum, Trump escalates public insults toward European leaders, posting a message that links the Chagos deal to “a threat to national security” and highlighting a private note from French President Macron, illustrating heightened diplomatic tension [4].

Jan 21, 2026 – Prime Minister Keir Starmer tells the Commons that Trump’s “great stupidity” remarks contradict his earlier support and serve as pressure over the United States’ Greenland ambitions, asserting that Britain will not yield on its Greenland policy [8].

Jan 26, 2026 – The UK Foreign Office reaffirms the Chagos handover as the best path forward despite Trump’s criticism, while Minister Stephen Doughty decries a Conservative “wrecking amendment” in the Lords that stalls the bill, and Parliament enters a “ping‑pong” stage over concerns about breaching the 1966 UK‑US treaty [2].

Feb 1, 2026 – Maldives President Mohamed Muizzu announces a proposal to assume Chagos sovereignty while preserving the U.S. base, pledging to seek parliamentary approval in the Maldives and positioning the move as a “Maldives‑first” strategy amid Indian Ocean power rivalry [7].

Feb 5, 2026 – Trump warns that the United States will militarily secure Diego Garcia if any future development threatens the lease, citing “very productive discussions” with Prime Minister Starmer and asserting a right to reinforce the base by force if necessary [6].

Feb 18, 2026 – Trump posts a direct warning to Prime Minister Starmer not to “give away Diego Garcia,” calling any transfer a “blight on our Great Ally,” while the U.S. State Department officially backs the UK‑Mauritius agreement and Chagossian activists stage a protest on the atoll against the handover [1].

Future (2026) – The Maldives plans to submit its parliamentary bill on Chagos sovereignty within weeks, aiming to keep the Diego Garcia base operational under a new sovereign framework, while the United Kingdom expects the UK‑Mauritius treaty to be ratified by Parliament later in the year and to commence the £101 million annual lease payments [7][2].

Future (2026) – The European Union discusses possible retaliatory tariffs on U.S. goods if Trump proceeds with his Greenland pressure campaign, indicating that trade measures could be deployed as leverage in the broader strategic dispute [8].