Authorities of Panama and Greenland have repeatedly said they won’t hand over any territory to Trump, with Panama’s president declaring that the canal "is going to stay in our hands forever," and Denmark’s prime minister insisting “Greenland is not for sale.”

The president-elect sees overseas territory as vital to U.S. interests and suggests he isn’t bluffing in threats to take over allies.

Few took the president-elect’s combative comments at face value, but they still sent a shudder through a country that has been invaded by the United States before.