Some of the purported concessions that led to a 30-day pause on the tariffs were things Canada and Mexico had already done before Trump’s threat, but it’s complicated.

Trump’s misguided belief that inside of every Canadian there is an American waiting to get out is a misconception that is actually older than the U.S. itself. Its history, however, offers a cautionary tale for Trump because it has been responsible for some of America’s most humiliating foreign policy failures.