I’d argue a bit to the contrary. Mr. Obama and team actually pulled off a remarkable regime change in Syria. The Neocon position is to make every nation a little U.S. but comes with a ridiculous refusal to demand the defeated set up a republIc style government. All styles of excuses are made ranging from fear of being called a colonialist to “they” can’t understand democracy. In Syria Obama’s team wanted to (a) weaken Iran and (b) remove a dictator who was too close to Russia. Little concern was given to what came next because you don’t know - it was an excellent piece of “we’ll cross that bridge when we come to it” thinking. Trump/Biden/Trump pulled off the same thing (but at a slower pace and not as coordinated) in Iraq by slowly dismantling Iranian militia efforts in and around Baghdad.
While I question if Trump has the focus, he could do the same in Iran. Destabilize the government, weaken their military, and promote change from within. Like Syria it could be done with air strikes, help from Mossad, and a handful of SOF types. Go slow, go easy, and let the Iranians do their own heavy lifting.
