Daniel Ikenson explains for Cato Institute readers why the Trump administration is wrong to base new tariffs on national security concerns.

By any objective measure, the degree and nature of U.S. reliance on imports of steel and aluminum do not threaten national security. President Trump’s claiming so was a smokescreen. The president wanted the domestic authority to impose tariffs, and invoking Section 232 of the Trade Expansion Act of 1962 was a foolproof way to get it.

The statute gives the president the broadest possible discretion to define and mitigate a “national security threat.” Because he can modify the tariffs or exempt countries from its reach practically on a whim, Trump has amassed the leverage he wants to bend U.S. trade partners to his will: Buy more U.S. products and I’ll drop the tariffs! Curtail your exports and I’ll modify the scope! Ramp up your NATO spending and I’ll call off the dogs!

Those who share Trump’s worldview might call this strategy ingenious. It is certainly unconventional, provocative, and possibly unhinged. Whatever you call it, Trump’s gunboat diplomacy is a major departure from the policy continuity of the last 13 U.S. administrations, and it presents a grave threat to the international trading system and the global economy.

Not since Herbert Hoover has a U.S. president been so cavalier about the consequences of protectionism. Never has a president been more dismissive of the importance of trade to our prosperity and security. Never has a president been so impervious to the lessons of history.