Open this photo in gallery: Prime Minister Mark Carney arrives and greets U.S. President Donald Trump prior to a meeting at the White House in Washington, on May 6.Adrian Wyld/The Canadian Press John Rapley is a contributing columnist for The Globe and Mail. He is an author and academic whose books include Why Empires Fall and Twilight of the Money Gods. The respectful reception given to Mark Carney at the White House on Tuesday, when compared with the ambush to which the administration subjected Ukrainian President Volodymyr Zelensky, has many wondering if the Prime Minister has brandished a secret weapon....