Islanders who were forced to leave their remote Indian Ocean home to make way for a U.S. military base half a century ago protested outside the U.K. Parliament on Monday.

The U.K. has agreed to hand sovereignty of the long-contested Chagos Islands, an archipelago of more than 60 islands in the Indian Ocean, to Mauritius, in a deal to secure the future of a strategically important U.

The deal that’s been announced is a rare win-win moment in international relations, with all the relevant actors able to claim a meaningful victory.