It is my understanding that the Joint Comprehensive Plan of Action (JCPOA) exchanges a limitation of the nuclear activities of Iran against a reduction or even abolisment of the sanctions against Iran.
On 8 May 2018 the US withdrew from the agreement, while the other signatories (Iran, Russia, UK, Germany, China, France and EU) kept supporting the agreement. Since withdrawing, the US reimposed sanctions agains Iran, including secondary sanctions. It is my understanding that the practical effect of the secondary sanctions is that the sanctions are back to a level that matches at least the pre-JCPOA level. This despite European efforts to blunt the effect with the creation of a Special Purpose Vehicle. Which makes me wonder where the upside is for Iran in sticking to the JCPOA.
Apart from possible goodwill that may come with being considered men of their word, what is, at the moment, the benefit Iran is getting from adhering to the JCPOA?
I am aware that Iran is threatning to violate the JCPOA in a near future. I'm not asking about consequences or likeliness of that happening.