The surprise appearance by Iranian Foreign Minister Javad Zarif at the G7 summit in Biarritz this week has inevitably raised hopes that, despite deepening tensions between Washington and Tehran, a diplomatic breakthrough might be in the offing.  Zarif’s presence at the French resort was due to an invitation he had received from French President Emmanuel Macron, the summit’s host, who is said to be spearheading European efforts to save the 2015 nuclear deal.

Relations between the US and Iran have deteriorated sharply since US President Donald Trump announced he was withdrawing from the nuclear deal last year and imposed a wide range of punitive sanctions against Iran. Tehran has responded by resuming work on uranium enrichment, a vital process in the development of nuclear weapons, and by attempting to disrupt shipping in the Strait of Hormuz, one of the world’s most important trade arteries.

With concerns growing that these tensions could result in open conflict between Washington and Tehran, it was hardly surprising that  Zarif’s presence in Biarritz should create speculation that a diplomatic solution might be possible.

This view was encouraged by comments made by  Trump at the summit, during which he praised  Macron’s attempts to bring Tehran to the negotiating table, and even offered to meet with his Iranian counterpart, President Hassan Rouhani, if the right circumstances presented themselves.

At the very least  Trump appeared to be signalling his backing for  Macron’s diplomatic engagement with Tehran, even though Washington’s confrontational approach to the Iran issue is very much at odds with efforts by key European powers such as Britain, France and Germany, to save the nuclear deal.

The personal rapport between the French and American leaders were clearly evident after  Macron hosted the US president at a private lunch, prompting  Trump to tweet afterwards that his French host was doing a “great job.” While the primary lunch conversation focused on  Trump’s threat to impose tariffs on French wine imports if Paris followed through on its decision to impose a digital tax on American tech giants such as Google, Facebook and Amazon,  Macron also raised the issue of Iran, and the importance of resolving the current crisis through negotiation.

He persuaded  Trump to agree, in principle, to meeting with  Rouhani, a significant achievement in itself as it would be the first such meeting between American and Iranian leaders since the Tehran hostage crisis of 1979-81.

While the entente cordiale between  Macron and  Trump should help ease tensions in the transatlantic relationship, the idea that it will bring Iran to the negotiating table remains remote

“It’s the beginning of something,” commented  Macron after lunch. The French president even offered a nuanced appraisal of Washington’s more confrontational approach to the Iran issue, remarking that the American approach “creates pressure, and conditions for a better agreement.”

Negotiating a better deal with Tehran has, after all, been the main driving force behind  Trump’s decision to withdraw from the 2015 agreement that his predecessor Barack Obama helped to agree with other major world powers.

In common with most Republicans, the president has consistently argued that the deal is flawed because it only focuses on specific areas of Iran’s nuclear programme and does not address wider issues, such as Tehran’s ballistic missile programme and its increasingly bellicose conduct in the Middle East.

And while the entente cordiale that was clearly evident between  Macron and  Trump should go some way to easing any tensions that may exist in the transatlantic relationship, the prospect that it might result in Iran returning to the negotiating table still remains remote.

For a start,  Trump’s offer to meet with  Rouhani met with an immediate rebuff from Tehran, which said that he would not entertain such a meeting without Washington first agreeing to lift economic sanctions, a request the Trump administration is unlikely to countenance.  Zarif even went so far as to accuse Washington of “engaging in economic terrorism against the Iranian people."

Moreover, Iran’s insistence on continuing with its military meddling in the affairs of Arab states is hardly conducive to creating the circumstances necessary for a resumption of negotiations.

Another key factor that could work against the prospect of negotiations being resumed between Iran and other world powers is the differing approach of the Europeans and Americans to the Iran issue.

This is most clearly evident in the approach most European powers have adopted towards the new US-led naval force that has been set up in the Gulf to protect merchant shipping. Despite repeated requests from Washington for other nations to contribute to the force, to date only Britain, Australia and Bahrain have agreed to support the US-led maritime security initiative in the Gulf.

The writer specialises on defence and international affairs