The thing that the Trump Administration does not seem to realize is that Iran was under a pretty stringent regime of sanctions for three decades without seriously hurting the Iranian economy. What did eventually hurt them (and brought them to the table to negotiate the nuclear deal) was because the Obama Administration convinced the other members of the P5+1 (the U.K., France, Russia, China, and Germany), plus the rest of the EU and Japan, to impose their own stringent sanctions against Iran. Those multilateral sanctions are what crippled the Iranian economy. Thanks to its oil wealth and the abundance of non-american customers, Iran had been doing okay under years of American-only sanctions.
So unilaterally re-imposing sanctions is not going to hurt Iran that much. For it to hurt, the other major economies would have to joint the effort. They are not going to join in the effort unless they think that Iran is violating the deal. No one will believe the Trump Administration's claims that Iran is violating the deal if they tell the New York Times two months ahead of time that they will "find a way to' claim that Iran is violating the deal, and will reach that conclusion in October no matter what the country actually does.
So unilaterally re-imposing sanctions is not going to hurt Iran that much. For it to hurt, the other major economies would have to joint the effort. They are not going to join in the effort unless they think that Iran is violating the deal. No one will believe the Trump Administration's claims that Iran is violating the deal if they tell the New York Times two months ahead of time that they will "find a way to' claim that Iran is violating the deal, and will reach that conclusion in October no matter what the country actually does.
