Trump took out the nuclear sites because Iran said they would continue enriching Uranium. They were getting closer to weapons-grade enrichment and Iran would not negotiate, so BOOM. Trump gave them plenty of chances to make a deal and they wouldn't do it.

Trump is not a neocon like Bush was. His only objective was that Iran should never have a nuclear weapon. He accomplished that and made the world a safer place. This isn't like Iraq. There is no regime change by the US. There is no nation building and no troops on the ground. If regime change happens it will be done by the people.

So far Iran and Israel have agreed to a ceasefire. I guess Iran finally decided to negotiate after all. They've been beaten and we'll see what happens next.