In a diplomatic move, UK Returns Chagos Islands to Mauritius in Historic Treaty Amid Controversy. The United Kingdom has officially signed a treaty to return sovereignty over the Chagos Islands to Mauritius, ending more than 50 years of British control over the Indian Ocean archipelago. The agreement, signed on May 22, 2025, represents a significant step in global decolonization and a long-overdue recognition of Mauritius's territorial claim.