This is probably Donald Trump's biggest mistakes, his refusal to certify Iran's compliance with the JCPOA nuclear deal with Iran and his fullout abrogation of it by announcing the reimposition of full economic sanctions against Iran, although we had not fully undone those sanctions anyway. An immediate victim in the US of this action will be Boeing workers who were to benefit from a $3 billion contract Boeing had with Iran, now cancelled by order of the US government. Needless to say, Trump has simply lied repeatedly about this matter, claiming the Iranians are not in compliance, when the IAEA and all other parties to the agreement say they are. Trump has strutted some reports stolen by Israeli intelligence, but those show almost nothing we already did not know, most particularly that Iran did have a covert nuclear weapons program prior to 2003 that it shut down.
I have posted on this topic regularly over a long period of time, going back all the way to the predecessor of this blog, MaxSpeak. I shall not reiterate all that I have said over those years, although I think my track record has been pretty good. I have long heavily relied on Juan Cole's Informed Comment for information on what is going on in Iran, and his track record on that has been excellent.
Two conflicting points come out, one suggesting bad things happening, one suggesting maybe not so bad. The bad is that Trump appears by all reports to simply have no plan beyond reimposing sanctions. Apparently he and his advisers think they can topple the regime, that economic unhappiness by Iranian citizens frustrated at failing to get much in the way of economic benefits from the JCPOA will rise up and overthrow the regime. But the more likely reaction will be for Iranians to move to support the regime against this clearly unwarranted and hostile act by the US. Of course apparently the Israeli and Saudi governments might like to have us engage in military action against Iran, which would be truly disastrous, but that does not seem to be in the works anytime soon. Anyway, it appears that aside from undoing yet another thing Obama did (lots of criticizing Obama and Kerry in his announcement), he really seems not to know what to do next. What I really wonder is if he truly believes his own lies that the Iranians have not been keeping to the deal.
The more positive fact is that all of the other participants of the deal: Russia, China, UK, France, Germany, and the EU, have all openly criticized Trump for this action and are not reimposing sanctions. Indeed, they seem to be acting so they can get around the effects through banking by the US to keep doing business with Iran, such as by using the euro instead of the dollar. This means that while Iranian leaders made noises about exiting the deal themselves and starting up their centrifuges again, maybe they can be talked out of doing that by the other parties to it. That would simply leave the US alone with its unemployed Boeing workers paying the price for this rank stupidity of Trump's. Let us hope for the best at this bad moment.