Donald Trump’s proposed takeover of Greenland is causing rifts inside Nato that have resulted in officials withholding intelligence sharing with the US. Sources from both sides of the Atlantic warn that the US-UK security relationship is at its lowest ebb since the 1950s, putting European security at risk. For more than 70 years, the special relationship between Britain and America has been a cornerstone of the Western alliance, with intelligence and military officials working together to combat all manner of threats, from direct war to clandestine operations. But Trump’s ambitions to acquire Greenland for national security reasons is destroying trust...