The U.S. is the world’s largest consumer market by a factor of 3. So it’s more accurate to say “Give me what I want or I’ll take away a sizable chunk of your customers, potentially causing you financial ruin”
You and I both know that the U.S. won’t just magically and instantly stand up its own production to replace your countries market, but in this case he just needs American companies to start importing from a different foreign country with lower tariffs. The effect this has on your country depends on how much your country’s GDP comes from exports to America, but it’s potentially very harmful.
As an American this sucks because long term, long after this dude is gone, our trading partners will have already adjusted who they’re exporting to in order to absorb a loss like this, and I doubt that’d change for decades.
Plenty of EU countries export a significant portion of their extra-EU goods for export to the U.S. , many of which are around 20-25%. Ireland tops the charts with a whopping 46%.
Overall goods you’re still talking about ~10%. I’m sure that number will be shrinking substantially over the next decade.