The US exited the Joint Comprehensive Plan of Action last year over objections to its limited timetable and its failure to address issues including Iran’s missile development and support for regional terrorist groups. The remaining members of the P5+1 group of nations have since been working to keep it in force, and European leaders have expressed concern over the potential for tensions to dramatically escalate.

Those concerns have arguably been substantiated over the past two months, since the re-imposition of secondary sanctions on all importers of Iranian oil reportedly precipitated new threats from the Islamic Republic. The danger of attacks on American personnel and allies led to the accelerated deployment of a US aircraft carrier, after which point Iran apparently attacked six commercial tankers before shooting down an American drone last week, which the regime claimed was over Iranian territory.

The US rejected the justification cited by the Islamic Revolutionary Guard Corps and insisted that the surveillance craft had been at least 21 miles away from the Iranian coast at all times. Nevertheless, a news outlet close to the Guards reported on Friday that Tehran had filed an official complaint with United Nations Security Council over the supposed “aggression” against Iranian airspace.

The report by Tasnim News Agency also quoted Deputy Foreign Minister Gholamhossein Dehghani as saying, “Tehran reserves the right to respond firmly if the U.S. repeats the violation.” This echoed a warning uttered the previous day by Speaker of the Iranian Parliament Ali Larijani, regarding the potential for a “stronger reaction” the next time Iran feels threatened by an American aircraft.

Additionally, Amir Ali Hajizadeh, the head of the IRGC’s aerospace force, was quoted as saying that Iran had shown restrain by only shooting down the drone, as opposed to also targeting a manned aircraft that was flying nearby. This assertion of greater military capability is certainly questionable, given that the IRGC had failed to shoot down another drone days earlier, and that the manned craft possesses countermeasures that were absent in the downed drone. Nonetheless, such threats may serve as fodder for American efforts to convince European allies of the need to collectively counter Iranian aggression.

Those efforts were amplified on Thursday by simultaneous meetings with representatives of various allies and partners. US President Donald Trump was in Japan that day for the meeting of the G-20, wherein Iran was among a number of important topics discussed. Meanwhile, Brian Hook, the State Department’s special envoy for Iran, met with representatives of the UK, France, and Germany to participate in discussions of the future of the JCPOA despite the US absence from it.

Hook explained in no uncertain terms that Trump’s decision to withdraw did not give Iran the right to ramp up its production of nuclear material, something the regime has threatened to do if it does not receive satisfactory economic benefits under the agreement. Mousavi set an arguably low standard for such benefits during his own meeting with the other five remaining signatories of the JCPOA on Thursday. “If the Europeans take a step and operationalize Instex, it should meet our needs,” he said.

“Instex” refers to the Instrument in Support of Trade Exchanges, a payment mechanism set up by the three European signatories earlier this year with the stated goal of facilitating transactions with the Islamic Republic which circumvent US sanctions. Questions have swirled about the practicality of that plan since it was first conceptualized, and although Instex has been formally established it has never actually been used to conduct transactions that are not already permitted under humanitarian exceptions to the nuclear deal.

Although Europe remains formally committed to upholding the agreement and is still urging Iran to break with its plans to exceed limits on uranium enrichment, it is increasingly unclear how committed they are to operationalizing Instex. It is also possible that ongoing Iranian provocations, including the pending ultimatum and the recent drone shoot-down, have altered European decision-making in this matter. What’s more, the Europeans are regularly exposed to arguments from the Trump administration and its supporters asserting that the economic sanctions are having the desired effect and that Tehran may soon agree to a more restrictive deal.

It is impossible to say with absolute certainty whether or not Iran’s leaders will break from their preexisting commitment to “resistance” and the rejection of standing offers of negotiation with the US. But it is well-established that the sanctions are having a meaningful impact on the Iranian economy. Reuters reported on Friday that Asian imports of Iranian oil fell last month to their lowest point in five years, as countries moved toward partial or complete compliance with newly-unfettered US sanctions.

At the same time, CNBC that a survey of oil experts showed surprising levels of optimism about the effect of those sanctions upon the global oil market. While nearly a quarter of respondents expressed the belief that limited missile strikes would be carried out before the dispute was resolved, the vast majority said they expected petroleum prices to remain the same or to edge only slightly higher while the dispute is still ongoing. This suggests that the pressure resulting from US-led sanctions is and will remain largely one-sided, with few consequences for the US and its allies.

Furthermore, the possibility of Iranian capitulation was seemingly underscored by some of the public commentary coming out of Tehran both before and after Mousavi’s claim that the European Union was facing its last chance to save the JCPOA. The Iranians had previously warned that they would exceed limits on Iran’s stockpile of low-enriched uranium by Thursday. But after that day came and went, they revised their estimates to say the limits would not be exceeded until after the weekend.

If that violation takes place, the Islamic Republic will supposedly accelerate its enrichment activities in order to exceed the level of fissile purity permitted under the nuclear deal. This is expected to take place on July 7, but it remains to be seen whether Iran will stand by that deadline. And even if it does, the nation’s ambassador to the United Nations has suggested that the JCPOA could still be salvaged after the fact. The Associated Press quoted Majid Takht Ravanchi as saying that Iran’s forthcoming actions could be quickly reversed as soon as the regime sees the desired economic gains.

Of course, the US government and its military are concerned that such gains would be channeled into Iran’s domestic and foreign paramilitary forces, and thus into more provocative gestures like the drone shoot-down. It is likely that some European policymakers already share those concerns. But also, the White House is using every opportunity to communicate the threat to its fellow Western powers.

ABC News reported on Friday that acting Secretary of Defense Mark Esper is planning to return to Brussels in mid-July to provide allies with a more detailed “history of the Iranian threat.” On Thursday, Esper participated in a meeting of NATO at the Belgian capital, and he urged other member states to join the US in condemning Iran’s recent actions and to participate in a maritime defense program set up by the State Department and the Pentagon in the wake of tanker attacks.

Secretary of State Mike Pompeo had previously promoted the program to Middle Eastern allies under the name “Sentinel.” Saudi Arabia reportedly embraced the idea, although it gave no indication of formally signing on after providing a readout of Pompeo’s meeting with King Salman and Crown Prince Mohammad bin Salman.

Even as Pompeo, Esper, and others work to build a broad coalition and confront Iranian provocations directly, each of them also continues to emphasize the Trump administration’s commitment to avoiding military conflict. “Our strategy is at its core an economic and diplomatic one,” Esper said in Brussels on Thursday. And although he warned Iran against mistaking “restraint for weakness,” the Secretary of Defense also evoked the administration’s confidence that economic and diplomatic approaches will force a resolution that is favorable to the West.

Supporters of the strategy tend to regard such an outcome as also being favorable to the Iranian people. After noting that the White House was prepared to move the restrictions on Iran’s economy from an estimated 80 percent to nearly 100, Treasury Secretary Steven Mnuchin headed off criticism of the effect on the civilian population by highlighting the continued application of humanitarian exemptions.

While Iranians are suffering from high levels of poverty and unemployment, these things precede the American “maximum pressure” strategy, and critics of the theocratic regime tend to attribute them primarily to economic mismanagement and an emphasis on force-projection in lieu of serving the public interest. The Trump administration’s separate statements about the Iranian regime and the Iranian people lends credence to the notion that its ultimate aim is to use sanctions as a means of encouraging domestically-driven regime change.

This conclusion gained in plausibility early last year when the US president embraced a nationwide uprising in the Islamic Republic, which gave rise to a number of slogans that appeared to endorse a wholesale change of government. Those slogans, often attributed to the People’s Mojahedin Organization of Iran, have been repeated in a number of subsequent protests, including some that closely coincided with the imposition of new US sanctions. Supporters of the PMOI and other Resistance movements point to this phenomena as evidence that the Iranian activist community is in favor of foreign sanctions on its own government, even at a time when Europe remains on the fence.