Donald Trump is hardly the first president to impose tariffs to prop up domestic industries. As recently as 2002, George W. Bush, in an ill-fated, short-lived effort to rescue the steel industry and garner support in steel-producing swing states, placed tariffs on selected steel products.

But Trump may be the first president to use tariffs on a specific product as a means of applying diplomatic pressure on an ally — at least a one-time ally — all under the guise of national security.

Angered by Turkish President Recep Tayyip Erdogan’s refusal to release American evangelical pastor Andrew Brunson, who is being held in Turkey, and with one eye on the imploding Turkish lira, Trump announced Friday — on Twitter, of course — a doubling of the tariffs on Turkish imports of steel (to 50%) and aluminum (to 20%).

Also read: Why Turkey’s crisis doesn’t spell doom for all emerging-market currencies

These are the same tariffs — 25% on steel and 10% on aluminum — that went into effect on June 1 on imports from Canada, Mexico and the European Union because those imports posed a threat to U.S. national security, at least in the estimation of the Commerce Department.

Trump had already imposed sanctions on two top Turkish officials in connection with Pastor Brunson’s “unjust detention.” But the opportunity to hit Turkey with additional tariffs was just too tempting, opening the door to Trump’s new and different applications of trade policy.

“Tariffs are not generally used as a part of a sanctions regime to change political behavior,” said Douglas Irwin, professor of economics at Dartmouth College and author of “Clashing over Commerce: A History of U.S. Trade Policy.” “More often you would see embargoes or prohibitions,” not a tariff designed to protect a specific domestic industry.

Are we to believe, based on Trump’s latest tariff escalation, that a country in economic crisis — Turkey’s currency is collapsing, inflation and debt levels are soaring, and economic policy is increasingly in the hands of an autocrat — poses an increased threat to the national security of the U.S.?

When I wrote that sentence, it was intended as rhetorical. Then I saw the statement released by Commerce Secretary Wilbur Ross.

“Doubling the tariff on imports of steel from Turkey will further reduce these imports that the Department found threaten to impair national security as defined in Section 232” of the Trade Expansion Act of 1962, Ross said. (Turkey is the world’s eighth largest steel exporter. It ranks 51st in aluminum exports.)

No area of economic policy gets the president as exercised as trade. Just imagine if Trump were to take out all of his frustrations with allies and foes alike by imposing tariffs, just as he did with Turkey. The possibilities are endless.

NATO allies aren’t coughing up 2% of their gross domestic product for the common defense quickly enough to please Trump? Hit the hold-outs with tariffs.

North Korea’s pledge of denuclearization turns out to be empty words with no follow through? Add tariffs to the economic sanctions already in place. (So what if North Korean exports to the U.S. are zero?)

Negotiations with Canada on the North American Free Trade Agreement aren’t proceeding apace? Threaten to impose tariffs on Canadian-made cars. (Wait, Trump has already done that.)

Tariffs have deleterious side effects when they are used, or misused, for economic purposes. The protected industries may benefit, but Americans pay higher prices. Manufacturing supply-chains are disrupted, forcing businesses to find alternative sources of the raw and intermediate materials they need to produce finished goods.

To employ tariffs for non-economic reasons is counterproductive — unless one lives in a world where strong-man tactics trump diplomatic skill. Making Turkish steel imports more costly is not going to secure the release of the American pastor. It does nothing to address the alleged espionage charges for which he is being detained. It harms Americans, angers allies, and triggers retaliation.

On Tuesday, Erdogan said his country planned to boycott U.S.-made electronic products. And he blamed outside forces for the lira’s precipitous decline and the nation’s other economic woes.

“One of the many things wrong with this kind of economic sanctions is that it gives the other country an excuse for its economic mismanagement,” said Dan Griswold, senior research fellow at George Mason University’s Mercatus Center, where he is co-director of the Program on the American Economy and Globalization. “Trump has thrown a lifeline to Erdogan.”

Trump is unlikely to appreciate that tariffs are an undiplomatic means to achieve a diplomatic end with Erdogan. But one thing that is sure to resonate with the commander in chief, as Griswold noted, is that his tactics are helping an adversary.

Your move, Mr. Trump.