How this trade war is different from all other trade wars

If the on-again, off-again tariff announcements by President Donald Trump have struck you as unusual, that’s for good reason. Nothing like this has ever happened before.

That’s the estimation of Dartmouth economic historian Douglas Irwin, whose 2017 book, Clashing Over Commerce: A History Of US Trade Policy, is the leading work on the subject. I called him for perspective. He told me that what we were experiencing was way outside the historical norm. One man alone has risked the first global trade war since the 1930s by

raising tariffs to levels unseen for more than a century

. The president’s actions, he said, represent a “big break with history”.