President Donald Trump says he will slap a 100% tax on movies made outside the United States — a vague directive aimed at protecting a business that America already dominates.

Claiming that movie production “has been stolen’’ from Hollywood and the U.S., Trump posted on his Truth Social platform that “I will be imposing a 100% tariff on any and all movies that are made outside of the United States.’’

It was unclear how these tariffs would operate, since movies and TV shows can be transmitted digitally without going through ports. Also unclear is what it would mean for U.S. movies filmed on foreign locations — think James Bond and Jason Bourne — or what legal basis the president would claim for imposing the tariffs.

The president had first issued the threat back in May. He has yet to specify when the tariff might go into effect.

Movies are an odd battleground for a U.S. trade war. “Unlike any other country’s film industry, U.S. movies are the most accessible, well-known, and best performing due to the numerous language options and worldwide reach provided by U.S.-based studios,’' trade analyst Jacob Jensen of the center-right American Action Forum wrote in a July commentary.

In movie theaters, American-produced movies overwhelmingly dominate the domestic marketplace. Data from the Motion Picture Association also shows that American films made $22.6 billion in exports and $15.3 billion in trade surplus in 2023 — with a recent report noting that these films “generated a positive balance of trade in every major market in the world” for the U.S.

Barry Appleton, co-director of the Center for International Law at the New York Law Center, warned that other countries may retaliate with levies on American movies or other services. In movies, “Brand America is way, way ahead,’’ he said. “What this policy does is actually cook the golden goose that’s laying the golden eggs.’’

Tariffs are Trump’s go-to solution for America’s economic problems, a tool he likes to use to extract concessions from other countries. Reversing decades of U.S. support for lower trade barriers, he’s slapped double-digit tariffs on imports from almost every country on earth. And he’s targeted specific products, including most recently pharmaceuticals, heavy trucks, kitchen cabinets and bathroom vanities.

Unlike other sectors that have recently been targeted by tariffs, movies go beyond physical goods, bringing larger intellectual property ramifications into question.