Trump is playing a very dangerous game with Iran. In an ideal world the hard liners would simply cave in to White House demands and change their entire foreign policy. Trump, Bolton, Pompeo and co seem to think this will foster a coup against them, but they seems fanciful in the extreme. And even if they did, that would not necessarily be s good thing for the ME. It’s the Sunni Moslems who’ve posted the biggest threat there with ISIS. And much as we all deplore Assad, for the Irsnians simply to withdraw from Syria now would likely lead to an upsurge in the war there. Iran is credibly a malign influence but the Israelis have demonstrated that they can take them out with little or no resistance.
As it is, sanctions will put up oil prices as markets lose Iranian oil again. And while the previous deal was flawed, at least it had the benefit of allowing in inspectors.
And as noted, it won’t instil much confidence in anyone that the USA can be trusted to keep to agreements