In late September 2026, an American sanctions deadline became a regional test of power. Washington had imposed an aviation blockade of Iran, but to do so it did not need to close Iranian airspace. Instead, it threatened the airports, fuel suppliers, ticketing systems, and service companies that make international aviation possible, forcing governments in the region to weigh access to the United States financial system against the risk of Tehran’s retaliation. Azerbaijan moved before Washington’s deadline. Georgia, Iraq, Oman, the United Arab Emirates, and Turkmenistan followed with different combinations of flight bans, service denials, and overflight restrictions. Tehran first responded with sweeping warnings and then, on September 26, denied that military retaliation was planned. The sequence exposed a widening gap between Iran’s coercive rhetoric and its neighbors’ risk calculations—and placed Azerbaijan’s decision at the center of a broader realignment in the South Caucasus. Armenia, which kept its aviation and political channels open with Tehran, offered the essential counter-case.

The American Lever: Turning Sanctions into an Aviation Blockade

The campaign began by redefining civil aviation as strategic infrastructure. On August 24, the U.S. Treasury placed Iran’s aviation sector under Executive Order 13902. On September 8, OFAC sanctioned 36 targets, including 27 Iranian airlines and third-country firms accused of servicing Mahan Air, a privately owned carrier that is Iran’s largest, or helping it acquire aircraft. FinCEN simultaneously warned financial institutions about Iranian aviation procurement, and OFAC suspended three general licenses. The design mattered as much as the blacklist: pressure shifted from Iranian carriers to the foreign companies and services on which they depended.

On September 21, Treasury Secretary Scott Bessent made clear how the sanctions would work. Starting September 23, he warned, airports and service providers that fueled Iranian aircraft, handled their landings, or sold their tickets could be excluded from the dollar system. The threat turned an American designation into a choice for every regional airport. Even governments unwilling to endorse Washington’s strategy had to weigh the political benefit of ties with Tehran against the systemic cost of U.S. secondary sanctions.

The early disruption allowed Washington to declare “Operation Economic Outcast” a success. Bessent linked the campaign to the rial’s collapse and claimed that 80 to 90 percent of Iran’s international flights had been shut down. Those figures are official U.S. claims rather than an independent measure of the blockade’s overall effect, but the operational impact was evident. The administration’s reported willingness to consider a narrow waiver for pilgrimage flights between Iran and Najaf also showed that the pressure architecture could be selectively eased without abandoning the campaign’s central objective.

The Domestic Price: Isolation Moves from the Runway to the Street

The sanctions struck an economy already weakened by war, pressure on oil exports, and a naval blockade. The rial traded at more than 2.2 million to the dollar on September 2 and more than 2.5 million by the end of the month. Aviation sanctions were not the sole cause, but they gave Iran’s isolation a daily, physical form. A depreciating currency could be dismissed as a market abstraction; canceled flights, crowded border crossings, and journeys lasting several days could not.

Flight-monitoring data cited in the report indicated a sharp decline in international services within a week. At Tehran airport, only five Mahan Air and two Iran Air departures were recorded on a Sunday, compared with around ten each on previous Sundays. Travelers were redirected toward Turkey and Armenia, with agencies describing trips through the eastern Turkish city of Van that required two long bus journeys even before border delays. Connections on Chinese and Russian airlines became harder to obtain, while Turkish Airlines removed several Iranian destinations from its schedules and Emirates, Lufthansa, Austrian, and Qatar Airways reduced or suspended services.

Iraq highlighted the political sensitivity of the disruption. Baghdad, Najaf, Erbil, and Sulaymaniyah halted Iranian flights, severing routes heavily used by pilgrims. Najaf tourism companies said Iranian airlines accounted for about 90 percent of their business. Iraqi officials sought exemptions for medical treatment, education, and pilgrimage, while clerics and Iranian diplomats framed the closure as an affront to the region’s Shiite religious geography. Secondary sanctions thus divided governments internally: financial authorities faced one set of risks, while religious institutions, provincial businesses, and ordinary travelers faced another.

Tehran sought to recast the sanctions as a humanitarian assault. Iranian legal and human rights bodies argued that the restrictions endangered access to health care and called for international scrutiny. Yet reporting provides no firm September figures for pharmaceutical air cargo, airline revenue losses, or newly grounded aircraft. The most recent fleet figure in the source material predates the crisis: in July 2023, 139 of Iran’s 330 registered aircraft were grounded.

Conflict of Narratives

Between September 23 and 25, Iranian officials tried to turn a sanctions-compliance issue into a contest of deterrence. Mohsen Rezaei, secretary of the Supreme National Security Council, warned neighboring states that if Iranian aircraft were grounded, their airports might also lose access to Iranian airspace. Mohammad Mokhber, an advisor to Iran’s Supreme Leader Mojtaba Khamenei sharpened the message: regional airspace was “open to all or to no one.” Several parliamentarians went further, speaking of retaliation, attacks on palaces, and the suspension of fuel or electricity supplies. The language was intended to raise the political cost of compliance by portraying routine aviation decisions as participation in Washington’s campaign.

Despite their breadth, the threats ultimately proved ineffective: regional governments complied with Washington regardless. Tehran was then faced with a choice between escalation and reinterpretation. On September 26, the Supreme National Security Council secretariat denied any intention to retaliate militarily, instead citing potential non-military reciprocal actions. The Council attributed the escalation in public expectations to “false interpretations and quotes.” This retreat allowed continued diplomatic or administrative pressure while also showing that the initial rhetoric exceeded the state’s actual willingness to act.

Iran’s messaging split into competing narratives. Officials emphasized that flights to China, Russia, Turkey, Afghanistan, Pakistan, Armenia, Belarus, Tajikistan, Vietnam, and Malaysia continued, while diplomats challenged the sanctions under the Chicago Convention and appealed to the United Nations and ICAO. Hard-line media insisted that the air and sea blockade should be broken by force and warned that negotiation would signal weakness. Critical Iranian outlets, by contrast, blamed administrative incompetence for allowing sanctions to disrupt ordinary travel and urged active diplomacy before pressure spread to land borders.

This was not merely a communications dispute. If Tehran treated every act of compliance as an act of aggression, it risked multiplying its adversaries. If it imposed no costs for the closures, it risked weakening deterrence. The official shift toward legal protest and unspecified non-military retaliation was therefore less a resolution than an admission that Iran had no attractive escalatory option.

Azerbaijan’s Pivot and the New Geography of Compliance

Azerbaijan’s decision carried more strategic weight than a routine aviation notice. Baku suspended flights by Iranian airlines on September 22, before the American deadline, and publicly attributed the decision to U.S. sanctions. In practical terms, Azerbaijan prioritized access to the dollar system despite the risk of Iranian retaliation. In political terms, it signaled that geography, trade, and shared infrastructure no longer guaranteed Tehran deference from a neighbor increasingly aligned with Washington.

The timing cannot be separated from the March 2026 strike near Nakhchivan airport. Azerbaijan said Iranian drones injured two people; President Ilham Aliyev called the incident a terrorist act, while Tehran denied responsibility and pointed to Israel. Nakhchivan is also tied to the contested corridor linking Azerbaijan proper to its exclave, a route that Baku and Washington regard as strategically important. Although responsibility for the strike remains disputed, the episode hardened Azerbaijani perceptions of the threat and diminished Iran’s claim to being a predictable neighbor.

An Iranian Varesh Airlines flight from Tehran to Dushanbe in Tajikistan illustrated how fragmented regional flight routes had become. Turkmenistan’s refusal to allow transit forced the aircraft to return after roughly an hour. On a second attempt, reports indicated that the flight reached Dushanbe via Azerbaijan and Kazakhstan. Iranian outlets circulated a conflicting account claiming that Azerbaijan had closed its airspace. The evidence therefore supports a firm conclusion about Turkmenistan’s refusal but not about Azerbaijan’s role in the initial attempted routing.

Baku’s restraint after the suspension was equally revealing. Iranian commentary suggested that Tehran might reconsider concessions on access to Nakhchivan or the North–South corridor, yet the cited reporting records no formal diplomatic rupture. Only days earlier, the Tasnim News Agency, controlled by the Islamic Revolutionary Guard Corps (IRGC) had praised a “new chapter” in bilateral relations. Iran thus avoided turning the aviation dispute into a broader confrontation, suggesting that the costs of escalation with Azerbaijan constrained the retaliation implied by its public rhetoric.

Deterrence After the Threat

The aviation crisis offers a narrow but important measure of Iranian deterrence after the 2026 war. Tehran correctly understood that neighboring governments were not making neutral commercial choices: their compliance materially advanced Washington’s pressure campaign. Yet deterrence depends not on identifying hostility but on convincing others that the cost of cooperation will outweigh its benefits. In this case, the threat of losing access to the dollar system proved a greater and more tangible threat than Iran’s warnings.

Iran still has options short of military action. Commentators proposed border exercises, navigation warnings, and repeated aviation notices (NOTAMs); Tehran could also complicate overflight access, customs procedures, energy exchanges, or cooperation on corridors. But each measure would carry reciprocal costs and risk encouraging closer coordination among states already hedging against Iranian power. By September 30, no punitive action against a specific country or airport had been documented. Iran’s concrete response remained diplomatic and legal: letters to the United Nations, an appeal to ICAO, and a reported complaint to the International Court of Justice.

The result is a gradual erosion of Iran’s deterrence. In other words, most neighboring countries do not fear possible Iranian retaliation. Iran remains a threat, but it is less threatening than in the past. In addition, Iran itself contributes to that erosion of deterrence: the more threats the regime makes and the fewer it carries out, the more credibility it loses. Of course, financial calculations are also important: the U.S. Treasury warned of financial penalties for all countries that do not comply with Washington’s aviation blockade on Iran. The risk of U.S. financial penalties appears to outweigh the risk of angering Tehran. 

Armenia’s Open Door to Iran

However, one country has not yet demonstrated unequivocal compliance with the U.S. aviation ban. Flights from Tehran continued to appear on the Zvartnots airport schedule, and Iranian reporting continued to list Armenia among the destinations served by domestic carriers. The Armenian Civil Aviation Committee issued no public declaration in the cited material. Continued flights, rather than a diplomatic statement, were therefore the clearest indicator of policy.

Yerevan also sustained high-level political engagement. Prime Minister Nikol Pashinyan met with Iranian President Masoud Pezeshkian on September 24, emphasizing the expansion of cooperation and regional stability. Parliamentary and security officials held meetings with Iran’s ambassador during the same period. The land border remained open, offering Iranian travelers an alternative route to Yerevan as air connections elsewhere diminished.

Armenia continued discussions with Azerbaijan and the United States on the “Trump Route for International Peace and Prosperity” (TRIPP), while Washington publicly committed to a deeper partnership. Yerevan’s approach can be characterized as hedging: maintaining ties with Iran as a vital neighbor and transportation outlet while simultaneously strengthening Western and regional initiatives that Tehran perceives as hostile.

Yet Yerevan must be told that it cannot have its cake and eat it too. Iran sees Armenia as its strategic lifeline, and those ties are also vital to its relationship with Russia. Thus, the primary objective of TRIPP is to drive Iran out of the region. Finally, the Iranian regime is at war with the U.S. and Israel, not to mention its disruptive activities in the Caucasus and the Middle East. For all these reasons, Armenia’s noncompliance with the U.S. Treasury’s requirements regarding Iranian aviation cannot go unnoticed by Washington.