President Trump shocked many yesterday with a surprise announcement of new steel and aluminum tariffs. As of next week, all imported steel products will be subject to a 25 percent tariff, with aluminum being hit with a rate of 10 percent. Calling for "free, fair and SMART TRADE!" in a tweet defending his decision, the President's protectionist move is intended to shore up the struggling U.S. steel industry. With the possibility of a trade war on the horizon, which countries are set to be most affected by the changes?

While China are often accused of damaging the US economy by flooding the market with cheap steel, they were actually only the 11th largest import country last year. In actual fact, the countries which will be hit the hardest by these new tariffs are in some cases key allies of the United States. Canada, for example, was the most important steel partner in 2017 with a total of 5.7 million metric tons flowing across the border.