Though the president-elect's rhetoric is unusual, for over a century a succession of US presidents have tried to gain control of Greenland.

While Trump has cited “national security” reasons for wanting to acquire the island inhabited by about 56,000 people, there’s another big appeal that he’s been leaving out of his press conferences. Greenland is a treasure trove of minerals the U.S. needs to compete with China, and the island hasn’t been quick (enough) to fork them over.