Not our problem. Also very easy calculus for the Brits. Give the island away now, and you might as well be handing it over to the Chinese at some point in the future.

That island is THE place to have if you care at all about the Persian Gulf.

Which is why they're insisting on keeping the base.

There's no doubt that maintaining control of the islands - and not just the base - is of some benefit to western security interests. But insisting on maintaining sovereignty over the entire archipelago has costs as well, especially after they've lost their case at the ICJ and had the UN issue a resolution ordering them to get out. The UK can certainly tell the UN to pound sand and just continue to violate the UN Resolution and maintain control over a portion of their former colony which has been found by every relevant international institution to violate international law. The question is whether the costs are worth the strategic benefits. Especially when a larger goal is to try to contain Chinese influence in the region, not just maintain as many physical military assets as we can.

In some ways, it's an elegant solution - they keep the base, but let Mauritius become the sovereign over the islands again. Much like the situation in many of our bases in foreign countries - when we have a base in Korea or Germany, we're not taking sovereign control of the area and making it part of U.S. territory, but simply have an agreement with the government. It's not as secure as having sovereign control over the archipelago - but it also removes the provocation and diplomatic costs associated with maintaining a colonial foothold and continuing the expulsion of the formerly native population.

It's a tough situation. There's arguments for and against, and it's probably a close call which is better. But it's not a stupid solution, by any means.