I agree that you are correct in this statement, althought if USA or Israel decided to nuke a country without a MAD recourse, that would be another can of worms. There's multiple reasons no country did that after Hiroshima. Even Russia refrained themselves of doing that in Ukraine after all these years.

Allow me to do a slight modification on my assessment: Iran found out they won't need a nuclear deterrent to avoid ANY future aggression; modern, cheap drones and conventional missile loadouts will do just fine. Money they would continue spending on nuclear enrichment can be better spent elsewhere, military.