First Iran, Now What?

For a president that prided himself as one that stopped wars, not started them, Donald Trump has certainly done an about face on that one, hasn't he? While going into Venezuela wasn't a war in arresting Nicholas Maduro, it was basically a regime change of a foreign country. And he has gone into Iran with the specific intent of insuring they would never get a nuclear weapon, if not changing the regime. But now there's Cuba on the table? Why?