I’m not sure I agree with your argument but all of it made sense until you started talking about Cuba.

Iran knows that the US population really really doesn’t want a ground invasion. Right now, we have lost a handful of lives from missiles hitting US bases, but it’s not the same as a ground war.

Cuba, however, would very much get a ground invasion if they start striking the US with missiles. It’s not even a question. And I also assume their leaders are not religious fanatics with any interest in martyrdom.