I spent last weekend crossing half the globe with Prime Minister Mark Carney, to spend a few hours with European leaders in Yerevan, the stunning Armenian capital, before crossing all the way back to Ottawa. Mr. Carney was the first non-European leader to be invited to a meeting of the European Political Community, a grouping that brings together the 27 European Union member states with allies and neighbors, including Britain and Turkey, as well as aspiring members such as Ukraine and Albania. This meeting happens twice a year, and it’s mostly a chance for the leaders to talk about pressing...