A trade war is coming. President-elect Donald Trump this week said he would open his presidency by inflicting new tariffs on imports from Canada, Mexico and China. The U.S.-China battle over trade could have the biggest geopolitical impact. It's not clear which side would come out the winner.

Donald Trump is altering global trade with a new tariff plan aimed at Canada, Mexico, and China. It includes a 25% tariff on goods from neighbouring countries and a 10% levy on Chinese imports to tackle migration,

What is a tariff, what is the purpose and who ultimately pays? As President-elect Donald Trump, a self-described "Tariff Man," prepares to take office again, the role of tariffs in global trade is as relevant as ever.