is the united states capable of regime change in iran?

well, that depends on a number of factors, most importantly russian involvement.

here's the thing: i don't imagine that putin is particularly ensconced with the iranian form of government, & the iranians themselves are less than excited about allowing the russians to move in, as they don't tend to go home, either. but, if the iranians & russians can make a defense deal - which they have in fact already done - then that forces america to react on the ground, because those russian air defenses.....what they do is force the americans to use stealth bombers, which they are almost certainly unwilling to do.

and, this is the part of the situation that few americans, or canadians, or members of the nato-alliance in general are truly cognizant of: whatever you think of trump's words, the reality is that his threats are hollow.

the only real strategic option that the americans have against the iranians is nuclear, and you're insane to put that option on the table.

so, is the audience domestic, then?

clearly.