Why is Denmark JD Vance’s white whale? In spinning up a diplomatic crisis with Denmark that recalls the geopolitical posturing that preceded World War I, the vice president is not just risking what’s left of the Pax Americana but scuttling global trade and destabilizing Europe.   Vance’s wife, Usha,  was supposed to take a ladylike cultural tour of Greenland last week , but officials in the region called her proposed trip a “provocation,” and she and her husband ended up stuck on a U.S. space