Let's See of a Treaty Signed by The United States is Worth the Paper it's Printed On

In 1916, the United States bought the Danish West Indies, now known as the U.S.Virgin Islands, for $25 million. As part of the deal, the Americans agreed not to object to Denmark's claim to Greenland.

Of course, Mango Mussolini, like his ideologial inspiration, hasn't met a deal that he wasn't willing to tear up. It'd be fun if the Danes then snuck troops into St. Thomas and reoccupied the place.