You are correct about Trump not being smart, and that he's being manipulated by others. Also Subwater is correct, Trump does not want WAR. He will saber rattle and maybe even attack Iranian troops in Syria but the chance of a direct attack is very low. as much as Mattis hates Iran, he does not want that either. That leaves Kushner and Natanyahoo. These two could still make a lot of trouble for Iran, it's been told that Kushner was a major force behind the Tillerson sacking. McMaster is also against a direct confrontation with Iran, there is an article that describes him and an Israeli military official screaming at each other in a meeting because they came to D.C. asking U.S. to attack Iran and Hezbollah in Syria, and Mcmaster did not want to risk an open war with US troops nearby(maybe that's why he will get fired soon).
The events will likely go like this: U.S. withdrawal from JCPOA, the Europeans will stay put but will go along with new sanctions, Iran may or may not take the bait. (Don't underestimate the stupidity of our hardliners). They will counter Iran in Syria more forcefully because their goal is to keep Syria fragmented and weak, and hurt Iran financially. The way forward for Iran is to stay in the deal no matter how bad it is and sew up Syria......one last thing the second biggest enemy Iran faces after Israel is UAE, they've spent a tremendous amount of money behind the scene and they've pulled a lot of strings to demonize Iran around the world.....I would even say that they're the reason for the recent S.A. and Israel thaw that we are witnessing.