On a chilly June day off the coast of Greenland, Emmanuel Macron, France’s president, and Mette Frederiksen, Denmark’s prime minister, boarded a Danish warship in a show of defiant solidarity. It was a cheeky piece of diplomacy. Mr Macron’s “hands off” message was partly directed at America’s Donald Trump, who has threatened to annex the Danish territory. “Greenland is not to be sold, not to be taken,” Mr Macron declared. But the French president’s message was also intended for Europeans: they need to stick together, stand up for themselves and stop clinging to dependence on America.