The long-awaited deal on the Chagos Islands was reached because a number of international court decisions ruled that Britain's presence on the island was contrary to law. The absence of a deal would have restricted the base's operational effectiveness, and by securing an agreement — which was welcomed by all Five Eyes allies, including the U.S. — the U.K. has been able to legally guarantee its presence there for generations to come.

President Trump is right that the decision to throw away of the Chagos Islands was an act of stupidity and self-sabotage. Though the needless degredationdegradation of Britain's security is no justification for an unlawful seizure of Greenland, Trump's intervention does give Starmer the chance to finally change course over Chagos before it is too late.