The mess in the Middle East is forcing states into actions that previously appeared unimaginable. Sworn enemies are suspending or at least compartmentalising grievances.

The idea that an American secretary of state would praise Iranian military operations in Iraq would have been beyond comprehension last year. No-one would sensibly have predicted that Turkey would remain largely silent as Kurdish Peshmerga consolidated their grip on the oil-rich region around Kirkuk. Russia and the West may be sliding into the abyss over Ukraine, but they co-operate closely in the Iranian nuclear negotiations.

And taking cold-hearted pragmatism to further heights, there are reports of Islamic State (IS) selling oil to its mortal enemy, the Assad regime.

In some cases, the unifying threat of IS has thrown up resolutions to old problems, such as the recent announcement of a long-needed agreement for sharing oil revenues between the federal Iraqi government and the Kurdistan Regional Government. Bringing both Qatar and the Gulf Co-operation Council into the anti-IS coalition seems to have helped dampen down an escalating confrontation between Riyadh and Doha.

On the other hand, Tehran’s increasingly forceful involvement in Iraq has only deepened the anxieties many Sunni states feel about rising Iranian power. The view in the GCC is that the Americans first handed Iran the keys to Iraq and then refused the chance to break its axis with Syria. Worst of all, they believe Obama’s desperation to strike a deal on the nuclear issue has encouraged Iran to flex its military muscles.

The involvement of Saudi and UAE pilots in the air campaign against IS was supposed to symbolise Washington’s new multilateral approach in the Persian Gulf. Since Iranian jets joined the fight with America’s blessing, Gulf involvement in the air war has become conspicuously less evident.

Iran’s Phantom F-4 jets, supplied by America to the Shah 40 years ago, now strike jihadi forces armed with US military hardware captured from an inept Iraqi army funded by American taxpayers. Whatever this says about US foreign policy over the last generation or two, it’s certainly not edifying.

And yet, despite all the chaos and improvisation, it is possible to discern some broader trends in the Middle East.

Come together

The Obama administration is by no means abandoning its interests or allies in the region, but it is far less interested in playing a unilateral policing role than certain of its predecessors. Outside Congress, there is a growing sense that America’s core alliances with Israel and Saudi Arabia have not helped the cause of regional stability. If the Saudis eventually abandon the idea that they can rely on US security guarantees, then their defining relationship with Washington could become that of global competitor in the oil market. Greater self-reliance could result in more co-operative security arrangements. Just as likely, however, is a military build-up that could exacerbate an already febrile region.

On the other hand, diplomacy between Iran and the US has benefited from Obama’s attempt to demilitarise US policy in the Gulf and the growing rift between his administration and Saudi Arabia and Israel.

Inside Iran, the perception of declining US hegemony is welcomed by realists concerned with Iranian national security and revolutionaries looking to vindicate an anti-imperialist stance. In a policy debate dominated by complex technological analyses, it is often forgotten that a more secure Iran is less likely to want to pursue nuclear weapons technology in the first place.

Here’s hoping.EPA/Ronald Schlager

Logically, therefore, if Iran’s leaders believe America is less willing or capable of playing regional policeman, they are more likely to feel secure and probably more willing to negotiate. Put another way, one look at the past 10 years shows that rapprochement would be highly unlikely if Washington was projecting more power and threatening to bomb Iran.

Getting there

The combination of a more pragmatic faction in Iran, shared security interests in Iraq, and Obama’s increasingly bullish attitude to hardliners in Congress are all good reasons to be reasonably optimistic about a positive outcome in the nuclear negotiations.

There is still a risk of total derailment, of course. The failure to seal a deal by the November 2014 deadline has provided a seven-month extension for hardliners on both sides to poison the process.

The falling price of oil and the lack of significant sanctions relief will damage President Rouhani’s economic credibility, while Washington’s powerful anti-Iran lobby will cite the extension as further evidence that the wily clerics are spinning the talks out as they creep towards weaponisation. Familiar Republican voices are already talking up war as the only viable option.

Still, there was an unexpected shock at a Senate Foreign Relations Committee hearing when the carefully selected experts, all sceptics of the nuclear deal, lost the script and warned that adding more sanctions now would be a spectacularly bad idea.

The most positive news of all is that Iran’s supreme leader, Ayatollah Khamenei, continues to instruct hard-line factions to back the talks.

Ever the pragmatist, Khamenei also maintains that America cannot be trusted to negotiate in good faith, preparing the ground for an “I told you so” if no agreement is reached. One look at his twitter feed also shows the difficulty America will face in taking the moral high ground on human rights after the summer of racist policing scandals and the Senate report on CIA torture.

Steady hands

When Iran next meets with the P5+1 negotiating group (the US, UK, France, China, Russia and Germany) the task will be clear. The parties must figure out how to maintain the West’s red line of a one-year breakout time – the interval required to enrich enough fissile material for one weapon – while also accepting Tehran’s condition of recognition of its right to industrial-scale enrichment.

A recent analysis by the Crisis Group presents the most sensible way forward: Iran should trade the postponement of industrialised enrichment for guaranteed access to enriched nuclear fuel and the recognition that it has the right to rapidly expand its enrichment program after a period of five to ten years.

The talks also need to work out how the sanctions can be wound down. The Crisis Group’s solution is again quite sensible: the P5+1 should agree a road-map consisting of three clearly defined target dates for a phased lifting of sanctions.

The US Congress could be a major spanner in the works here, whether by passing new sanctions, or by refusing to remove existing legislation even if the P5+1 and the IAEA give Iran a clean bill of health. This would, however, mean choosing a confrontation that American public opinion clearly doesn’t want over a peaceful solution supported by most of the world. Even for a Congress as polarised and sour as today’s, that would be a new level of madness.

Both sides will need to show flexibility and be sensitive to how their choices play out domestically. But the ingredients for success are there.

Given the current state of the world, failure would be a devastating blow, not just to the Rouhani and Obama administrations, but for international security. The hope of success, however faint, is to be cherished.

Christian Emery does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.