Canada retaliates with tariffs after U.S. trade talks fail, imposing 50% duties on $20 billion of Canadian goods.

Canadian Prime Minister Mark Carney vows to retaliate, says his country recognized that 'America has changed' and that the two countries would 'not return to our old relationship'

The United States is imposing 50% tariffs on $20 billion worth of Canadian products after last-ditch negotiations failed to resolve the latest strain in already tense relations…