Trump Just Announced Tariffs on Movies Produced "In Foreign Lands."

So... What the hell does this mean? Firstly, films are intellectual property, so how is it enforceable, and second, what does it mean if you use a US-based content aggregator like FilmHub or distributors like Indie Rights? Or ANY US-based distribution structure? Basically, if they're having to pay 100% tax on British films, we are we screwed (until it all goes away)?