The world is not a nice place in large areas. One of Bush's faults was that he thought he could transplant American ideals and political systems to other countries. That is just not practical. Does anyone seriously think the Shah was not preferable to the mullahs? He was oppressive in many ways but he was trying to bring Iran into the modern era. At least women did not have to wear drapes. And he was a reliable friend to the US. Since we helped engineer his demise can anyone say the Iranian people are better off? And then we had to turn to saddam to help keep the mullahs in check. At least when he and Manual went too far we took them out.
In foreign affairs you help those who help you. When we meddle in their internal affairs we tend to get in trouble.