[defrost]

Likely because:

    Between 1968 and 1973, the Chagossian (Îlois) inhabitants were forcibly expelled from Diego Garcia by the UK Government so that a joint US/UK military base could be established on the island.

    Many were deported to Mauritius and the Seychelles, following which the United States built the large Naval Support Facility Diego Garcia, which has been in continuous operation since then.

    In 2019, this action and continued British administration of the archipelago were deemed illegal by the International Court of Justice in The Hague, a ruling the United Nations General Assembly supported.

    In 2023, Human Rights Watch condemned the action as a crime against humanity.

[PeterHolzwarth]

An important detail to add to that, to ensure a complete picture is created of the situation, is that originally the atol was uninhabited. The French created a colony there of 60 or so people and slaves.

[defrost]

It was uninhabited in 1519, over 500 years in the past.

In the interest of completeness both Great Britain and North America were also once uninhabited.

[eesmith]

Umm, "people and slaves"? Do you really consider slaves to not be people?

Also, originally Iceland was uninhabited. The Norse created a colony there of - as you put it - "people and slaves". That equivalent history surely does not affect the legal status of the descendants of those people now living in Iceland. Why should it affect the people now living in the BIOT?