Tariffs Are a Costly (and Possibly Illegal) Mistake: Editorial

Amid the president’s blitz of tariff initiatives, the April “Liberation Day” scheme is an outlier. Rather than targeting specific products or countries to advance a policy goal, it imposed across-the-board duties, relied on vague justifications, and proved so harsh and omnidirectional that it induced a market crash. It was also premised on an arcane emergency-powers law — which may soon prove its undoing.

In announcing the tariffs, the White House asserted that persistent US trade deficits in goods amounted to “an unusual and extraordinary threat” and cited the International Emergency Economic Powers Act to impose a 10% baseline import duty, along ...