Trump's election promise to tear up the JCPOA agreement, which he calls one of the worst contracts, has not yet been accomplished. However, according to Rex Tillerson, Obama's successor believes that the United States should exit any deal which is not beneficial to the US, and it does not matter whether the European allies benefit from it or not.
In other words, in the recent situation of the Atlantic, considering the significant disputes between the United States and the European Union on some issues such as the Paris Agreement or NATO, Trump not only considers his country's benefit in a unilateral withdrawal from a deal that is not beneficial to the United States, but he also wants to put pressure on the European Union by rejecting the JCPOA, which he tried before by exiting the Paris agreement.
Nevertheless, Trump’s administration has twice decided to remain in the deal. However, for the third three-month period (starting about one month later) when the White House needs to reassess its commitment or unilaterally exit the deal, it has already taken some initiatives that may lead to the US withdrawal. One of Trump’s dissembles is that, according to him, Tehran is not committed to the spirit of the JCPOA.
Obviously, Trump's non-legal, ambiguous excuse under the title of “violating the spirit of the JCPOA” is not a sufficient claim to pull his country out from the deal that has been signed jointly with its allies. Inevitably, John Bolton, former ambassador of the United States in New York, has recently published a detailed description of such an excuse which proposes a detailed plan entitled “How to get out of the Iran nuclear deal?” 
“The vague and unclear word-making parts of JCPOA, the apparent benefits for Iran, the major violations and unpardonable behaviors of Iran in international arena, clearly and convincingly show that the JCPOA is a threat to U.S. national-security interests.”
The plan is so important that Zarif, the Iranian foreign minister, regarded it as a plan by someone who is not in charge, saying: “The plan will definitely be a huge failure for the United States and it will lead to the further isolation of America in the international arena.”
Zarif also pointed to Bolton’s previous detrimental ideas for the US illustrating: “Washington’s decade-long pursuit of Bolton-engineered policy to halt Iran’s uranium enrichment eventually had no result but a significant increase in the number of Iran’s centrifuges from 200 to 20000. It means Bolton’s policy caused a 19800 centrifuges progress for Iran.” 
Zarif's reaction toward someone who is not in charge in the United States is important because John Bolton is not just a former diplomat, but as Zarif said his ideas in the 1980s had virtually turned US foreign policy against Iran's nuclear case. Thus, now that Trump is in the highest official position in the US, he fears that Bolton's plan for the withdrawal of the US from the JCPOA, once again, will turn out to be US' official policy.
This is while John Bolton is personally a pioneer of presenting the plan to overthrow the Islamic Republic. He had attended the annual MKO gathering in Paris last year and the year before. He said in the meeting that “the regime's behavior has not changed. The only way is to change the regime and celebrate your victory in Tehran.” 
On the other hand, Zarif’s response to Bolton could be considered as the reaction of the Islamic Republic toward the US movements questioning the JCPOA. For instance, recently, in an unusual act, Nicki Haley, the US Ambassador in New York, visited Yukio Amano, Director General of the International Atomic Energy Agency (IAEA). The visit was considered unconventional because if the United States were willing to convey a message to the Director General, it could be transmitted by the US ambassador in Vienna; it therefore caused Iran’s sharp reaction. 
There should be a more important mission that just Nikki Haley could be responsible for, which was simply to put additional pressure on the Agency to inspect the “military centers” of Iran under the pretext of verifying the Agency of peaceful activities, which will naturally be opposed by Tehran and can subsequently give the United States more excuses.
Ironically, the US plan of IAEA inspecting Iran’s military facilities is a subject that Hassan Rouhani considered a possible, however unlikely, action. He said in an interview that “it is unlikely that the Agency accepts the US suggestion. Even if it does, we will not accept the bullying, and we will treat the agency based on the regulations.”
Clearly, Rouhani's statement indicates that it is likely that the Agency will inspect Iran’s military facilities. In this case, if Iran's military installations have to be inspected by the Agency (as happened in Iraq), we must consider the failure of one of Obama's achievements in foreign policy. The JCPOA, which was the product of two years of joint cooperation of the US with its European allies, is going to be torn apart by Trump.
Researcher at the Tampere Peace Research Institute /TAPRI