The Chagos Islands (also called the Chagos Archipelago) are a group of islands in the Indian Ocean, the largest of which is Diego Garcia. The islands are currently controlled by the United Kingdom as part of the British Indian Ocean Territory, but have been claimed by Mauritius since it gained independence from Britain in 1968; this claim has been supported by various international courts and organisations, including the ICJ. Diego Garcia is home to Naval Support Facility Diego Garcia, a British base leased to the United States.

In 2024, Britain announced a deal to transfer sovereignty of the islands the Mauritius; the deal proved controversial for various reasons, and there is speculation that the United States under Donald Trump will veto it.

This market will resolve to the country or countries that the islands officially belong to on 31 December 2049; if different islands are controlled by different countries, the market will resolve evenly to them (except for "They will be underwater / won't exist", which will resolve NO unless it is the case for all the islands). What matters is who officially owns the islands, not who has claims on it or leases any land on them.

For more information:

https://en.wikipedia.org/wiki/Chagos_Archipelago_sovereignty_dispute

https://commonslibrary.parliament.uk/research-briefings/cbp-10115/