Canada’s new leader, Mark Carney, has led the central banks of two separate countries through financial crises. As prime minister of Canada, he’ll be putting his fiscal policy bona fides to the test as the country prepares for a trade war with the US, Canada’s most important trade partner. The World’s Host Marco Werman learned more from Tari Ajadi, a political scientist at McGill University. He joined the show from Montréal.