President Donald J. Trump’s surprise announcement that he will seek to impose tariffs on steel and aluminum imports sent shockwaves around the world yesterday and roiled the financial markets. Whether those tariffs get implemented is open to debate. Many believe the reality show theatrics with which he made the announcement were intended to distract from the accelerating scandals that are engulfing his White House.

But if he really intends to enact the tariffs, which are opposed by many in his administration, it shouldn’t come as a surprise. Trump campaigned on the promise of “America First” and many of his actions in the first year of his presidency have been designed to deliver on that campaign slogan.