The United States have already stuck their nose into Afghanistan and Iraq and simply can't afford to waste valuable resources on parts of the world that have been fighting and killing each other since the beginning of time.
While the first part of your post was generally sound, it doesn't seem inaccurate to note that the current political situation in Iran is partially due to previous U.S. intervention in the country, not the population's own "perpetually disorderly conduct."
Now I would approve of allowing Israel bombing and obliterating their nuclear capabilities though
Israel is a small country, and it would only require decent mid-range missile capabilities for Iran to strike back against whatever hostile action the ruling administration chose to take, even without them having developed nuclear weapons of their own at this point. The facts that Iran's physical infrastructure reduces the possibility of a quick and clean Osirak-style "obliteration," that the Israeli government is opposed by Shi'a allies of Iran in southern Lebanon (Hezbollah) and a broadly restless Palestinian population that could be provoked to greater militant violence if they perceived a time of weakness or reduced military capabilities on that government's part (because of a confrontation with Iran), and that Iran's development of a nuclear energy program is permissible under the terms of the NPT and any military action is opposed by the current U.S. administration means that such action would be widely condemned and receive effectively no support all weigh in as factors against such an action.