Iran can’t trade with the US, other than some pottery and crafts, which amount for a million/year tops. Same with Russia - it’s not on the tariffs list, but it doesn’t need to be anyway. It’s good shock value, gets everyone talking about that
I don’t think any of this will work favorably to the US, just trying to think what their internal logic might be. The econ guys (Bessent & the other one the name escapes me) wrote a lot about this “3 step plan” in the past few years. So far they’re playing the step 1 exactly as written…