The British Empire is said to have invaded all but 22 countries in its history. But this empire, which was "not sunset", was forced during the twentieth century to abandon its colonies and recognize its independence in succession, so that there is little of it under its authority.

But a remote island in the Indian Ocean is still causing Britain a headache because of its repeated demand for the return of a small archipelago still under British occupation as defined by the United Nations.

A six-month UN deadline for Britain to return the Chagos archipelago to Mauritius expired on Friday (22 November 2019).

Britain, which has defied the UN resolution, says it does not recognize Mauritius' claim of sovereignty over the archipelago.

British rejection
As the deadline lapsed, the British Foreign Office issued a statement insisting it had every right to retain control of the archipelago, which it calls the British Indian Ocean Territory.

"The United Kingdom has no doubt about its sovereignty over the British Indian Ocean Territory, which has been under British sovereignty since 1814," the statement said.

"Mauritius has never had sovereignty over the British Indian Ocean Territory, and the UK does not recognize its claim."

For its part, the Government of Mauritius said at the end of the international deadline that Britain has now become "an illegal colonial occupier," according to the Prime Minister of Mauritius Pravind Jugnuth.

Mauritius says it was forced to relinquish the archipelago to the British colony in 1965 in exchange for independence in 1968.

Archipelago with three million pounds
Britain paid £ 3 million for the archipelago and declared it a territory under its name the British Indian Ocean Territory.

On May 22, 2019, the vast majority of the UN General Assembly voted in favor of the return of the Chagos Archipelago to Mauritius.The resolution was supported by 116 States, with only six against and 56 abstentions.

The United Nations said the decolonization of Mauritius "has not been done in a manner consistent with the right of self-determination", and therefore "its continued administration (by Britain) ... is an infringement."

The resolution demanded that Britain end its occupation of the archipelago unconditionally within six months.

The UN decision came just three months after the United Nations Supreme Court recommended that Britain leave the Chagos archipelago as soon as possible.

Notorious American base
Of the six countries that voted against the UN resolution, the United States, which has an air base on the island of Diego Garcia, one of the islands of the Chagos Archipelago, had created it at the invitation of Britain.

From that military base, US planes launched bombings in Afghanistan and Iraq.

Al-Qaeda was also reportedly used as a "black site" by the CIA to interrogate terrorism suspects.

In 2016, the base lease was renewed until 2036.

Chagossians demand return to their islands, which were abandoned by Britain (European)

What risks does Britain face?
For decades, Mauritius has called for the archipelago to be restored and has won international support recently, especially after Britain decided to leave the EU after the Brexit referendum, prompting Britain's traditional allies to vote against it or abstain in the United Nations.

The UN deadline was not binding, so no immediate sanctions are expected.

But the BBC's Andrew Harding believes that Britain's disregard for international calls could lead to slow and gradual sanctions, mostly on the part of institutions, that it may find itself outcasts in institutions as long as they are very important to them.

Harding explains that Britain no longer has a judge at the 14-member International Court of Justice in The Hague, and that in the future it will see another fact on the UN map that reflects the UN's vision of Mauritius' sovereignty over the Chagos Archipelago.

The British government had confirmed at the time of the UN resolution that it does not recognize the claim of sovereignty of Mauritius, but said it would honor a previous commitment to hand over the archipelago when it no longer needs it for defense purposes.

Displacement of the archipelago population
Between 1968 and 1974, Britain displaced thousands of Chagos and transported them over 1,000 miles (1,600 km) to Mauritius and Seychelles, where they lived in extreme poverty and were victims of discrimination.

Later, Britain repeatedly apologized for the displacement, which Mauritius Prime Minister Pravind Jugnuth said was amounting to crimes against humanity.

Mauritius is located in the Indian Ocean off the southeast coast of the African continent.

It is home to about 1.3 million people in a multi-ethnic, multi-religious and multilingual society, with Hindus, Christians and Muslims living side by side.