For the first time since a landmark nuclear deal was signed between Iran and six world powers - the US, UK, Russia, France, China, and Germany - in 2015, Iran is rethinking its strategy and possibly planning an exit.

On February 22, Iran has given an ultimatum that it will withdraw from the Joint Comprehensive Plan of Action (JCPOA) if it does not benefit economically from it and if major banks, companies and business entities continue to refuse to do business with Iran due to negative statements by the US president, Donald Trump.

"We cannot remain in a deal that has no benefits for us," Iran's Deputy Foreign Minister for Political Affairs, Abbas Araghchi told Chatham House in London.

Araghchi who is close to Iran's supreme leader, Ali Khamenei, and was one of the main JCPOA negotiators, accused President Trump of "violating the letter and the spirit" of the deal by creating a "destructive atmosphere".

For its part, the US has been threatening for months to quit the deal if its "disastrous flaws" are not fixed. In January, Trump delivered an ultimatum to his European allies: either fix the accord or the US would walk away from it by May 12 when the next US sanctions waiver is due to be ratified.

Trump identified three problems with the deal: its failure to address Iran's ballistic missile programme; the terms under which international inspectors can visit suspect Iranian nuclear sites; and the "sunset" clause under which limits on the Iranian nuclear programme start to expire after 10 years.

When other parties to the agreement rejected to "fix" these points, claiming they are all outside the boundaries of JCPOA, Trump proposed a hushed-up supplemental agreement that addresses "Iran's development or testing long-range missiles, ensures strong IAEA inspections, and fixes the flaws of the "sunset clause".

{articleGUID}

Araghchi's speech at the Chatham House was indirectly devoted to explaining why these issues are "illusional". He said the deal is only related to non-proliferation, and that IAEA after nine "tough" inspections had acknowledged Iran's compliance. He also ridiculed the objection to the "sunset clause" saying there is no such clause in the deal. "Iran's commitment to stay away from nuclear weapons is permanent," he said.

The Saudi factor

President Trump is reportedly entering into a new potentially lucrative atomic energy agreement with Saudi Arabia, which may explain why he is so adamant to tighten the conditions of the Iran deal. According to a report by the Washington Post, the Gulf kingdom is refusing to include in the billion dollar agreement any clauses that would restrict its uranium enrichment capabilities, unless the nuclear deal with its arch foe Iran is tightened.

Iran must have received the information on this new initiative from its European and Russian partners and put it together with other reports about cooperation between the US, Saudi Arabia and Israel for isolating Iran out of Syria and Iraq. All indications are that the US would probably never cancel the remaining sanctions and would seek ways of imposing more.

Araghchi said this atmosphere of uncertainly was "killing the deal"."It is like poison for the business community that wants to work with Iran," he told Chatham House.

In the last two months, a combination of factors has caused deep anxiety in the Islamic Republic. A stagnating economy has led to internal resentments with high youth unemployment feeding onto nationwide protests.

And this has been coupled with a barrage of threats and attacks of unilateral action from US officials and Israel. During the week-long nationwide protests in January, Trump's series of tweets sounded like he was calling for regime change in Iran.

In Munich, at the security conference Iran's foreign minister, Javad Zarif, signalled Iran's impatience if the US opts out of JCPOA without sanctions relief:

{articleGUID}

"I can assure that if Iran's interests are not secured, Iran will respond, will respond seriously," he said. "I believe it would be a response that means people would be sorry for taking the erroneous action they did," stressed Zarif.

Iran would, perhaps, continue to keep to its commitments until May 12, while leaving the door open for further negotiations provided JCPOA is implemented in full and sanctions are lifted by then as specified.

Iran would at the same time increase its militarisation to keep guard for potential attacks and invasions. The testing of its ballistic missiles, which it regards as unrelated to JCPOA, will continue as will its plans "to construct naval nuclear propulsion". Iran's leader has called for increased "defensive power".

Had JCPOA been implemented in full by now Iran might have been in a more receptive mood.

Under the circumstances, the moderate government of President Hassan Rouhani has little choice. It must improve the economy fast if it is to avoid further widespread unrest. Labour protests have continued in several cities across the country. Steel workers have been striking for over a week demanding payment of three months' overdue wages.

If the uncertainty over sanctions blocks Iran from improving business and international investment, then it would be forced to seek new partners and new deals, most likely with Russia and China.

The danger of that outcome is that Iran would roll back to hardline policies, at the top of which would be leaving JCPOA and returning to its full nuclear programme and an even more autocratic isolationist political structure at home.

If that's what President Trump prefers, then he's making a big mistake.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial stance.