After weeks of uncertainty it finally happened: Canada has been plunged into a trade war it desperately hoped to avoid. Even as it unfolds the path is unclear. Already there are signs that some tariffs could be reduced or removed, but it will cause pain on both sides of the border. Make no mistake, we are in a new era of Canada-U.S. relations. David Paterson is Ontario’s representative in Washington, and understands what's at stake and what's happening on the ground like few others. He was former VP at General Motors and BlackBerry, and was chair of the Canadian Chamber of Commerce. He talks to host Amanda Lang about what's motivating Trump's tariff attack, how he wins over U.S. lawmakers and why he doesn't think the U.S.-Canada relationship is permanently damaged.