Mark Carney, Canada's incoming prime minister, says he will confront -- head on -- the challenge his country is facing from its powerful neighbour. US President Donald Trump has imposed tariffs on nearly all goods coming from Canada. Carney has promised to push back with trade taxes of his own and is seeking to unite Canadians against this challenge from America. With elections on the horizon, how will this play out politically? And can Canada's close relationship with the US survive this turmoil?