The failure of the Islamabad talks to end the US-Israel war on Iran was hardly surprising, given the stark differences between Washington’s 15-point proposal and Tehran’s 10-point equivalent. The 2015 Joint Comprehensive Plan of Action (JCPOA), which capped Iran’s uranium enrichment, took more than two years to negotiate, and its roots actually reach back to 2003. The US vice-president, JD Vance, spent less than a full day in Islamabad for negotiations that included the nuclear question and several others.

The surprise was Vance’s explanation for the failure – that Iran rejected the terms presented by the US. The American side was not in a position to dictate terms because Iran stood firm when the 8 April ceasefire took effect. But Vance seemed to believe, as does his boss Donald Trump, that the Iranians had been defeated and the US didn’t have to budge.

Following Vance’s return, Trump, true to form, quickly upped the ante by imposing a naval blockade on all ships sailing to or from Iranian ports through the strait of Hormuz. A blockade is an act of war, so things are already dicey. They could get much worse if Iran responds to the blockage of its oil exports by attacking the energy infrastructure of the US-aligned Gulf monarchies, something it has already threatened to do. That would drive up the price of oil, diesel, liquefied natural gas (LNG) and other critical commodities. Trump might resume attacks on Iran and Israel would probably follow. Full-on war would be back. Hence the urgency of restarting talks.

So what next? Fortunately, neither side has ruled out further negotiations. Moreover, intermediaries – Pakistan and Egypt – are diligently working behind the scenes to bridge the gaps between Tehran and Washington. Both Tehran and Washington have reasons to avert renewed war. Trump knows more war will deepen the hole he dug by accepting the methodical assurances of Israeli prime minister Benjamin Netanyahu and his team that an unprovoked war on Iran would bring down the regime. Inflation is rising, his already low poll numbers are falling, and the midterm elections loom. Iran withstood a fearsome assault, but the massive damage it suffered will only increase if fighting resumes, making reconstruction harder and prolonging the economic hardship that has fuelled mass unrest in the past.

These circumstances are favourable to renewed diplomacy, but that requires a feasible framework. My potential framework doesn’t pretend to be comprehensive – Iran’s ballistic missile programme remains a live issue – but it does address the central issues in dispute.

First, it requires that the United States recognise Iran’s right to enrich uranium – which it has as a signatory of the non-proliferation treaty – for non-military purposes and subject to International Atomic Energy Agency (IAEA) safeguards. Enrichment would be capped at 3.67% – which was the 2015 JCPOA limit anyway – with electronic and onsite IAEA monitoring and the dismantling and storage of Iranian centrifuge cascades. Iran could go further by agreeing to cease all enrichment beyond the five-year maximum it has offered without acceding to Washington’s demand for a 20-year moratorium. After Trump ditched the JCPOA in 2018, Tehran no longer felt bound by its enrichment limit because he reimposed – even tightened – the sanctions that had been lifted in keeping with the agreement. Iran now has 440kg of 60% enriched uranium. The US would settle for supervised down-blending, rather than insist on its full removal. The enrichment agreement could run for 20 years, and be renewable.

My framework calls on Iran to make a written pledge not to develop nuclear weapons, in line with the injunction of the late Ayatollah Ali Khamenei, who was himself killed by a US-Israeli strike on 28 February. Iran’s government often cites his injunction, so it should be able to offer the no nuclear-weapons pledge. After Khamenei’s death, Iran’s foreign minister said he anticipated no major change in Tehran’s position, but Khamenei’s son and successor, Mojtaba, could help by reaffirming his father’s prohibition, in conjunction with a parallel Israeli pledge – guaranteed by the US and the members of the UN security council – to never initiate a nuclear attack on Iran. After being attacked twice in less than a year by Israel and the US, Iran may balk at renouncing nuclear weapons. That’s why the other parts of this framework contain compelling incentives.

Iran should drop its war reparations demand, which the US will never agree to pay. In return, the US lifts primary and secondary sanctions fully and all frozen Iranian assets are released. Iran also receives the right to levy its $2m (£1.5m) fee per oil tanker transiting the strait of Hormuz – providing Tehran commits to upholding the right of innocent passage, overseen and guaranteed by a coalition of countries from the region and beyond, including Russia and China. Given that the Gulf monarchies allowed the US to use their bases to wreak massive destruction in Iran, Tehran’s insistence on funds for economic reconstruction isn’t unreasonable. Moreover, the transit fee arrangement will end once reconstruction costs – which should be estimated by a neutral party – are met, and the surcharge will, as Iran itself proposed, be split with Oman, which is on the other side of the strait.

The US and Iran should sign a non-aggression pact, ratified by their legislatures and embedded in a UN security council resolution. Iran abandons its unachievable demand that the US armed forces fully withdraw from the Middle East, but the non-aggression pact offsets this concession, and Tehran and the Gulf states can sign similar agreements.

Ultimately, three conditions must hold for this – or any – plan to be adopted. First, Washington must make compromises, not Iran alone. Second, Trump must extend his 22 April ceasefire deadline and accept that talks of this complexity take time. Third, an Israeli attack on Iran could derail everything. While talks continue, Trump must stay Netanyahu’s hand.

• Rajan Menon is professor emeritus of international relations at Powell School, City University of New York, and senior research fellow at Columbia University’s Saltzman Institute of War and Peace Studies