How Will Trump’s Tariffs Affect Iran’s Steel Trade?

Who’s for a trade war? Apparently no one, except US President Donald Trump. 
His impromptu announcement last week of slapping tariffs on steel and aluminum imports set off worried and furious talks of potential retaliatory measures and market chaos.
The repercussions were quickly felt. Gary Cohn, Trump’s top economic advisor, resigned on Tuesday reportedly over frustration with the tariffs; the European Union prepared a “harsh and clear reaction” by drawing up a €2.8 billion list of proposed counter-measures, and Canada’s Prime Minister Justin Trudeau described Trump’s decision as something “absolutely unacceptable” which “makes no sense”.
The US president followed through on his promise on Thursday and levied a 25% tariff on steel and 10% on aluminum. He has, “at least at this time,” exempted Canada and Mexico from the measure, but the exemption’s continuation is tied to the fate of the North American Free Trade Agreement, from which Trump has repeatedly threatened to quit if the talks to reform it should fall apart.