The precise ideological lessons that Iran’s new leadership draws from the 110-day war may prove to be the overriding factor in determining whether negotiations with the US culminate in an agreement that verifiably prevents the country from developing a nuclear weapon – an outcome that could usher in a new era for the Iranian economy while also reshaping the Middle East.

Does this rapidly assembled leadership team, forged in the fire of war, still represent an Islamic ideological crusade – a description coined by Henry Kissinger – or does the acceptance of the memorandum of understanding, in the words of JD Vance, denote a desire for pragmatism?

The vacuum created by the invisibility of Iran’s injured supreme leader, Mojtaba Khamenei, makes this moment something of an interregnum. On Thursday, Khamenei published a letter saying he opposed the deal in principle but had deferred to the president, Masoud Pezeshkian, after being given undertakings that if the US demanded too much, he would not accept.

The rights of the country and the axis of resistance had to be protected, Khamenei said. Like his father and predecessor, Ali Khamenei, he has put himself in the enviable position of ensuring absolution from blame if the elected politicians get burnt dealing with the west.

His public intervention, on the eve of now-cancelled talks in Switzerland, may yet influence the balance of a charged debate inside the US administration as to the nature of Iran’s new, younger leadership.

On Friday last week, Donald Trump seemed to land on one side when he accused the Iranian leadership of being “very dishonourable people who don’t deal in good faith”.

That assessment appeared to chime with the views of John Ratcliffe, the CIA director, who warned his president that a significant gap separated the positions publicly expressed by Iranian officials from what they were saying privately. “Intelligence indicates that Iranian intentions do not align with the commitments made in the agreement,” Ratcliffe concluded, a source close to the discussions told Axios.

The hint was that Iran’s leadership team would either stall on a nuclear agreement or, worse, conclude they must secretly assemble a weapon since the strait of Hormuz would eventually become a wasting asset.

Few Iranians deny that the strait was decisive in proving the US could no longer impose global order unilaterally.

Payam Fazlinejad, a hardline editor of the magazine Naqd Andisheh, said: “History has also shown America that geography sometimes takes revenge on technology; part of the source of power lies in geographical straits, not in heavy military equipment. Iran has come to understand that it possesses a greater deterrent power than a nuclear weapon.”

But, like many others, Fazlinejad urged the leadership to break the never-ending cycle of war, negotiations and protests. “The country cannot afford a new miscalculation and must restore stability to the country,” he told Pezeshkian at a meeting of media editors this week. Politicians may have different prescriptions but it is clear the public crave a return to normality.

Trump, judging by his remarks at the G7 summit in Évian-les-Bains, has gone all in on a version of this analysis and, as a result, decided to embrace Iran’s leadership. On Tuesday, he described the country’s leaders – the third set with whom he has had to negotiate – as “the most rational group we have ever dealt with … They are not radicalised. They are looking to help their country.”

Trump’s team like to think they have been given in the last few weeks privileged access to the most senior figures in Tehran in a way that is unprecedented for US politicians since the 1979 revolution.

Vance, for instance, said the US had never got so close to the Iranian leadership. “The coolest thing about the progress we’ve made over the last few weeks is that you’re seeing people within the Iranian system – senior leadership, even IRGC officials – say: ‘You know what? We recognise the way that we’ve done business with the US for 47 years is a mistake.’”

He said it was the hardliners in Tehran who were playing up the benefits of the deal for Iran and playing down its drawbacks – an assessment that in fact is probably the opposite of what has been happening in the capital over the past two weeks.

In reality, it has been the most hardline faction, known as the Paydari Front and long opposed to engagement with the west, that has denigrated the deal. This group, linked to the former nuclear negotiator Saeed Jalili and prominent in the parliament, described the deal as a catastrophe and said ending the blockade now was premature.

Many of its members appeared at street rallies and on TV to denounce the negotiating team as a betrayal of the revolution and of the martyred supreme leader. Jalili’s brother Vahid, who runs much of the state broadcaster Irib, has provided a platform for critics of the deal, to the open frustration of Pezeshkian. Critics claim Irib is an inverted version of Fox News, suppressing diverse opinion.

The internal battle over the deal was, in some ways, a re-run of the arguments Iran went through when it signed the nuclear deal in 2015. The chief negotiator, the then foreign minister Javad Zarif, became a target of vitriol for years, accused of naively striking a deal with the “Great Satan”.

When Trump unilaterally withdrew from the deal in 2018, he severely undermined the faction that saw Iran’s opening to the west’s markets as essential. Ever since, the advocates of negotiation have had to overcome the reasonable argument that the US cannot be trusted. Currently it is Trump’s inability to control Israel in Lebanon that weakens the negotiations in Tehran.

Nevertheless, it still feels as if, despite Khamenei’s intervention, the hardliners are the ones who had to retreat. The advocates of a deal won not only an argument but also a power struggle. Mohammad Bagher Ghalibaf, the conservative-inclined consensus builder recently re-elected as speaker of Iran’s parliament, is probably – along with the Islamic Revolutionary Guard Corps (IRGC) from where he came – the most high-profile beneficiary of the war.

Ghalibaf was so confident of his position, he suggested a vote was taken at the supreme national security council on whether to accept the deal. Unusually, army members were allowed to vote as well. Only one person present opposed, reportedly most likely Jalili.

Key figures in the parliament, a possible roadblock, concede the memorandum is not a document that requires parliament’s approval.

In a long interview on Wednesday, punctuated by many personal pronouns as well as praise for national unity, Ghalibaf justified the act of negotiation and, implicitly, the concessions inherent in bargaining.

“My job is not diplomacy,” he said. “I am a fighter. But with the spirit and culture of a fighter I pursue diplomatic work. Our goal was to relieve the pressure and fire on the people. If this negotiation had not taken place, would such an event have just happened just by firing a missile? No.

“Our armed forces, compared to an enemy armed to the teeth, can wipe the floor with them, but could this have been possible without the support of the people? Never.”

But if survival in war was the primary objective, the big question now is how the government will behave.

The early clues, experts say, are that the new leadership is operating a new grand strategy, that it will be more authoritarian, more pro-China and more willing to listen pragmatically to the advice of the IRGC. Preparations for Ali Khamenei’s funeral hardly suggest Iran is morphing into a secular regime.

On the nuclear front, a deal is available, since the US has abandoned previous red lines. However, Kelsey Davenport, an Iran expert at the Arms Control Association, warned that discussions about the critical on-the-ground verification role of the UN nuclear inspectorate, and the regime’s willingness to accept a necessarily intrusive UN inspection regime, were still to be tested. Strict timelines were needed for Iran to report to the International Atomic Energy Agency, she said.

Ghalibaf also seems aware that the focus inside government needs to shift to address inflation and the currency markets. “We must take over the frontline from the launcher kids and relieve the people from economic pressure,” he said. “The criterion of success is shifting from repelling external threats to improving the economy.”

One way to do that is to not put all Iran’s eggs in the western basket. Ghalibaf, appointed as special envoy to China last month, emphasised a balanced approach between west and east.

Sina Toossi, a senior fellow at the Centre for International Policy, said: “For years, Iran treated China transactionally. They were ultimately seeking some kind of accommodation with the west, and were using China as a form of leverage. But they did not really deliver to China everything that China wanted.

“Xi Jinping visited Tehran in January 2016, the same month the JCPoA [joint comprehensive plan of action] was signed. During his visit, China and Iran signed a comprehensive strategic partnership agreement, but Iran gave all the contracts to European countries.”

Esfandyar Batmanghelidj, one of the best analysts of Iran’s economy, said: “Chinese business leaders and officials felt jilted. It was a strategic error by Iran not to prioritise relations with China. Ghalibaf is signalling he’s not about to make the same mistake.”

After all, few countries in the region are making progress without Chinese investments, but since 2018 US sanctions have made that investment in Iran near impossible.

Another unresolved problem is politics. Iranians who pinned their hopes on Trump’s promise that “help is on its way” feel abandoned. One said: “When you go in a taxi, to the stores, [or] talk to friends, no one is happy with the deal. We did not expect this in March. We did not want a Xi, or an Iranian Putin.”