President Donald Trump ordered a 25% tariff on steel and aluminum imports, escalating his efforts to protect politically important US industries with levies hitting some of the country’s closest allies.

The North American trade drama is unfolding against a backdrop of diverging economic performance that gives President Trump leverage in the trade war. Why it matters: The two nations are tightly linked by the trade patterns that the White House threatens to blow up.

President Trump announced potentially crippling tariffs against Canada, only to suspend them for 30 days. What will satisfy him remains unknown.