Between the US presidential election in November and the Iranian election next spring, there lies a window of opportunity to resolve the dangerous global impasse over Iran's nuclear programme.

And if everyone plays their diplomatic cards right, this geopolitical time bomb could actually be defused. That's the message in an intriguing behind-the-scenes report by the Guardian's diplomatic editor, Julian Borger.

New hope?

Last spring, intensive negotiations to reach a deal between the Islamic Republic and six major world powers (the US, UK, France, China, Russia and Germany) failed, after meetings in Baghdad and Moscow ended in stalemate. The six powers offered minor concessions on economic sanctions in exchange for Iran retreating from its uranium-enrichment programme, which they believe is a step towards Iran building a nuclear weapon (something Tehran has always denied). Iranian negotiators wanted sanctions to be lifted first, and everybody walked away frustrated and empty-handed.

Now, Borger writes, western negotiators say they're preparing another offer. "A 'reformulated' proposal will offer limited relief from existing sanctions and other incentives for Iran to limit the level of enrichment of its uranium stockpile," he reports, saying that they are aiming to "sequence the steps required to reach a deal to overcome the mutual distrust that helped sink previous rounds of negotiations, where each side appeared to wait for the other to make the first major concession."

An unnamed European official is quoted as conceding the last offers were nonstarters. "We recognise that the Iranians need something more with which they can sell a deal at home, and we will expect real change on the other side. It is about getting the sequencing right. That is what this next round will be about."

Who wins the US election will be a critical factor to the plan's success, too. "The plan assumes that either Barack Obama wins a second term, or that Mitt Romney wins but allows the diplomatic initiative to go forward unchanged," Borger admits, warning: "If a victorious Romney insists on a full policy review after taking office, the nuclear diplomacy could be derailed for months."

Time is running out

Borger's sources say the window of opportunity closes in the spring, when Iran holds presidential elections of its own. That's also when Israeli prime minister Benjamin Netanyahu has said Iran will cross a "red line" in its ability to produce a weapon, something Israel has vowed to prevent with military strikes if they deem it necessary.

Bottom line: everybody (except possibly Netanyahu) realises they're going to have to give something to get something. Recognising that Iran has legitimate reasons to distrust the west and giving them an incentive to negotiate could be the key to easing this standoff.

Fixing this problem could not be more urgent, not only because US-led sanctions are causing so much misery for the Iranian people (although this is reason enough). The alternative – a possible war between a nuclear-armed Israel and a potentially nuclear-armed Iran – is just too terrifying.

Learn more: New York Times reporter William J Broad makes a persuasive case against the current US position. The belief that sanctions alone will force Tehran to knuckle under seriously misunderstands the regime and the Iranian people, he warns.

Sources: Guardian, Avaaz, BBC, New York Times