Greenland is a security issue, not an overreach, US ambassador to NATO says Ambassador Matthew Whitaker argues that melting Arctic ice and rising global competition make Greenland central to U.S. and NATO defense. NEW You can now listen to Fox News articles! In an exclusive interview with Fox News Digital, U.S. ambassador to NATO Matthew Whitaker pushed back against growing European backlash over Washington’s focus on Greenland after France announced new military exercises with Denmark, saying