Does Canada need a customs union with the U.S.?

Canada’s happy trade arrangement with the U.S has ended. And while it seemed sudden and alarming, it was not totally unforeseeable to those watching the bigger shifts in global trade. Among those who predicted this moment, Roger Martin. He's the former dean of the Rotman School of Management and a best-selling author. He talks to host Amanda Lang about how globalization began to unravel, the problems with U.S.-Canada trade and why Canada needs to ‘ask the EU question.’