However, that mechanism has yet to function as it was supposedly intended to, which is to say that it has not been used for any transactions that were not already allowed under humanitarian exceptions to sanctions that were re-imposed and expanded after the US pulled out of the Joint Comprehensive Plan of Action last year. Since then, the three European signatories have remained largely committed to the deal alongside Iran and its allies China and Russia. But Iran has grown increasingly frustrated with the supposed lack of economic benefits associated with restrictions on its nuclear program.

Lately, the Iranians have acknowledged two violations of the agreement – larger-than-permitted stockpiles of nuclear material and higher-than-permitted levels of uranium enrichment – and President Hassan Rouhani has threatened that a third violation would be forthcoming in October if the Europeans did not take steps to counteract the effects of US sanctions. This would presumably involve the resumption of activities at the Arak heavy water plant, which could open a plutonium pathway to an Iranian nuclear weapon.

This situation is putting some strain on European commitments to upholding the agreement, but seemingly not enough to actually prompt the UK, much less France, to walk away from the agreement as the US did. The Europeans have repeatedly insisted that Iran move back into compliance with its obligations under the JCPOA, regardless of whether Iranian officials prove satisfied with the efforts of the INSTEX host and operators. Newly-elected British Prime Minister Boris Johnson repeated this insistence just ahead of the G-7 but also declared that there would be no radical change in his government’s approach to handling Iranian non-compliance or Iranian issues in general.

This statement stands in contrast to prior claims by at least one fellow British lawmaker, that Johnson was readying his government to follow America’s lead in pulling out of the nuclear deal. Nonetheless, White House officials continued to express optimism about the British position as late as Friday. In the course of his ascendance to the office of Prime Minister, Johnson has drawn various comparisons to US President Donald Trump, and these have helped to fuel expectations of a growing alignment between those two governments rather than between the UK and France.

The long-term prospects for either alignment were arguably left up in the air on Friday, when an anonymous British official confirmed that the UK was standing by the JCPOA, but was doing so at least partly out of concern about upsetting or alienating French President Emmanuel Macron before the G-7, which he is hosting. But in the short-term, the UK seems poised to at least tacitly defend Macron’s efforts at reaching an agreement with the Islamic Republic. The extent of those efforts came into sharper focus on Friday when the French President met with Iranian Foreign Minister Mohammad Javad Zarif at the end of his European tour. Zarif had previously visited Finland, Sweden, and Norway, where he reportedly discussed the crisis surrounding commercial shipping in the Persian Gulf, among other issues.

The meeting in Paris elicited praise from Zarif regarding Macron’s suggestions regarding the Iranian nuclear program and barriers to trade with the Islamic Republic. However, neither man would provide significant detail about what those recommendations were. This may raise alarm among particularly harsh critics of Iran’s theocratic regime, which include the Trump administration and various pro-democracy Iranian activist groups like the People’s Mojahedin Organization of Iran. The PMOI (MEK) and its parent coalition the National Council of Resistance of Iran (NCRI) have both roundly condemned the French and Scandinavian governments for playing host to Zarif even after he was placed under US sanction for allegedly acting as a conduit for regime propaganda and a mouthpiece for Iran’s Supreme Leader Ali Khamenei.

This activist groups have sought to highlight statements by Iranian French officials suggesting that Macron had put pressure on his own intelligence services in the run-up to Zarif’s visit, in order to discourage public reference to a thwarted terror plot targeting the NCRI on French soil in June 2018. Paris placed the Iranian secret service under sanction after determining that the order for the attempted bombing had come down from the highest levels of the clerical regime. But the regime’s opponents are now expressing concern that that incident may not lead to appropriate consequences, especially if Macron pursues an overly conciliatory strategy around the time of the G-7.

Last month, it was reported that Iranian authorities had arrested an Iranian-French academic for no discernible reason, possibly making her the latest in a long list of Western citizens and permanent residents who have been taken hostage in a bid to exert pressure on Western countries, in hopes of extracting new concessions. Some French government employees with past experience involving Iran and Iran-backed terrorism have concluded that the arrest of Fariba Adelkah was predicated upon hopes of trading her for Assadollah Assadi, a former Vienna-based Iranian diplomat who is currently facing charges for directing the effort to bomb the NCRI gathering near Paris on June 30, 2018.

It remains to be seen whether Macron’s government would be amenable to this exchange, which would in any event require Paris to intercede in Brussels, where Assadi is facing charges of terrorism. But prior French administrations have participated in similar swaps, as have other Western governments at various times, including the US. Half a dozen American citizens or permanent residents are currently known to be held in the Islamic Republic, but the White House has shown no interest in compromising on its maximum pressure strategy, and so the issue or potential prisoner exchanges may come to represent the extent of the gap between France and the US when it comes to Iran policy.

But at least until there is a more definitive account of Macron’s intentions, American officials are likely to downplay that divide. On August 21 in an interview with Bloomberg, the US State Department’s special envoy for Iran, Brian Hook, said, “We have had tactical disagreements but there isn’t any disagreement on end states.” He then went on to insist that the UK, France, and Germany all “share the same threat assessment” and recognize that “the Islamic Republic of Iran is the principle driver of instability in today’s Middle East.”

Such claims presumably form the underpinnings for the Trump administration’s optimistic statements about forthcoming alignment between the policies of the US and its European allies, particularly Britain. Assuming this optimism is at least partially justified, European policies might be expected to shift toward greater assertiveness as European leaders find reasons to perceive Iran as an even greater “driver of instability” than it has been in the recent past. And ongoing Iranian responses to pressure from the US may provide exactly those reasons.

Although Zarif used his European tour to repeat familiar talking points about a desire to avoid war, he came under sanction from the US in late July only after refusing a request for negotiations. This refusal was in keeping with various statements by other officials including Supreme Leader Ali Khamenei, insisting that no negotiations with the US would take place unless economic sanctions were first removed in their entirety. Furthermore, that position coincides with numerous statements, particularly from officers in the Islamic Revolutionary Guard Corps, describing readiness for conflict and even for victory over Western forces.

Such rhetoric continued in its outpouring just ahead of the G-7, as Iranian state media announced the unveiling of a missile defense system called Bavar-373, which is supposedly capable of tracking up to 100 targets simultaneously, before using six different weapons to intercept them. Shahrokh Shahram, a brigadier general in Iran’s regular army, reportedly said on Thursday night that the system is superior even to American systems like Terminal High-Altitude Aerial Defense and Patriot. A day later, Deputy Defense Minister Qassem Taqizadeh claimed that Iran also maintains other, highly accurate missile systems that it has not yet publicized.

But the Islamic Republic has a long history of using state propaganda networks to inflate its image of military readiness. Many unveilings of supposedly advanced weapons systems have been found to be merely superficial alterations of outmoded equipment, while others have apparently been altogether non-functional. These facts do not diminish Tehran’s impulse to antagonize the US with militarist rhetoric, but they may influence US allies’ response to that rhetoric.

For the time being, Iran may be relying on Western aversion to confrontational policies, in order to bolster the regime’s propaganda. That aversion is apparent in the fact that France and Germany have so far disregarded American requests for participation in a coalition designed to defend commercial shipping against Iranian threats. However, the UK did ultimately sign onto the plan, along with the United Arab Emirates and Australia, following weeks of escalating tensions driven by Iran’s attacks on and seizures of tankers in the vicinity of the Strait of Hormuz.

On August 15, authorities in Gibraltar ordered the release of an Iranian oil tanker that had been seized by British Royal Marines for violating European Union sanctions. But more than a week later, there was still no sign of reciprocal action from Iran, which seized a British-flagged vessel in retaliation in mid-July. The longer that vessel remains detained in Iran, the more European policymakers may question the prospects for productive negotiations with Iran. And this may in turn lead the British, and to a lesser extent the French, to reexamine their current strategy of opposing US-led maximum pressure on the regime.