In the years since the January 2006 election, Prime Minister Stephen Harper’s three Conservative governments have pursued a foreign policy so unlike what came before that it could be called the big break. The big break — or the Conservative transformation of Canada’s foreign policy — has been heavily criticized by academics, former diplomats, politicians and journalists, but it has also had a few defenders. This paper examines how the big break came about and what it looks like. It also seeks to place the transformation within the context of a foreign policy that was already in flux. The paper divides the arc of Canada’s engagement with the world from the end of World War II up until today into four periods: Laurentian coherence; Laurentian incoherence; Conservative incoherence; and Conservative coherence. Future governments may seek to reverse this Conservative reversal of the Laurentian approach, but given the breadth and depth of the Conservative coalition, at least some of the big break is likely to endure.