Iranian Airlines Sanctions: Can the U.S. Ground Flights Abroad?

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Introduction

The Iranian airlines sanctions can disrupt international flights even when carriers retain permission to operate in foreign countries. An airline may hold the necessary flight authorizations but struggle to serve a destination if fuel suppliers, ground handlers, or other businesses withdraw essential services. The United States can exert considerable commercial pressure through its sanctions system, but it cannot use those measures alone to close another State’s airspace or revoke permissions that State has granted.

On September 8, 2026, the U.S. Department of the Treasury announced sanctions against 36 targets, including 27 Iranian airlines designated under Executive Order 13902 (U.S. Department of the Treasury, 2026). The Office of Foreign Assets Control (OFAC) also suspended authorizations concerning payments for overflights of Iranian airspace, bunkering and emergency repairs, and temporary operations in Iran by certain civil aircraft. General License DD permits the wind-down of specified transactions previously covered by those authorizations until 12:01 a.m. Eastern Daylight Time on September 23. Its expiration does not itself prohibit every Iranian aircraft from flying internationally (OFAC, 2026).

The prospect of a wider disruption became more immediate on September 21, when Treasury Secretary Scott Bessent said that all Iranian airlines would be shut down worldwide on September 23. He warned that foreign businesses providing fuel, landing services, or ticket sales could lose access to the dollar system (CNBC, 2026). That warning concerns potential consequences for service providers; it does not establish that every supplier faces an identical legal restriction or that all Iranian international flights have ceased.

The distinction is significant under international aviation law. Article 1 of the Chicago Convention recognizes each State’s complete and exclusive sovereignty over the airspace above its territory. Article 6 requires State permission for scheduled international air services, while Article 5 addresses nonscheduled flights under different conditions (Convention on International Civil Aviation, 1944). The effect of U.S. sanctions on a particular route consequently depends on the applicable restrictions, the permissions governing that service, and the decisions of the governments and businesses on which its operation relies.

1. September 8 Sanctions and the September 23 Deadline

The U.S. measures announced on September 8, 2026, did not take the form of a single order prohibiting Iranian aircraft from flying internationally. The Office of Foreign Assets Control (OFAC) designated airlines and businesses under two executive orders, suspended several existing authorizations, and issued limited licenses for winding down specified transactions. Each measure affected a different set of persons or activities (U.S. Department of the Treasury, 2026, Treasury Grounds Iranian Airlines with Sweeping Sanctions Action; OFAC, 2026, September 8 Designations Notice).

The legal basis for the airline designations had been established two weeks earlier. On August 24, the Treasury Secretary determined that the aviation sector of the Iranian economy was covered by Executive Order 13902. OFAC relied on that determination to designate 27 Iranian airlines on September 8. Other targets were designated under Executive Order 13224, as amended, for conduct that Treasury associated with the previously sanctioned Mahan Air (U.S. Department of the Treasury, 2026).

September 23 subsequently became the focus of a broader public warning. Speaking to CNBC on September 21, Treasury Secretary Scott Bessent said that Iranian airlines would be shut down worldwide on September 23 and warned of consequences for businesses continuing to provide them with essential services. His statement described an anticipated operational outcome. It did not withdraw landing permissions issued by foreign governments or establish that every Iranian airline had ceased flying (CNBC, 2026, Squawk Box Interview with Scott Bessent).

1.1 Airline designations and aviation support networks

OFAC designated 27 Iranian airlines for operating in the aviation sector of the Iranian economy under section 1(a)(i) of Executive Order 13902. They included Iran Aseman Airlines, Iran Air Tour, Qeshm Air, Sepehran Airlines, and Zagros Airlines. The aviation-sector determination supplied the basis for their designation; Treasury did not announce a separate finding that every airline on the list had transported weapons or military personnel (Executive Order 13902, 2020, s. 1(a)(i); U.S. Department of the Treasury, 2026).

The other nine targets were eight businesses and one individual designated under Executive Order 13224, as amended. Treasury associated them with aircraft procurement, cargo services, or sales activities involving Mahan Air. Unlike the aviation-sector designations, these measures rested on specified relationships with, or support for, persons already subject to counterterrorism sanctions (U.S. Department of the Treasury, 2026).

Treasury alleged that ECT Aviation Support LLC in the United Arab Emirates and Sky Phoenix in Türkiye acted as intermediaries in the transfer of U.S.-origin aircraft to Mahan Air. It also designated Ibrahim Ali Mohamed Mohamed Mahran, whom it identified as an owner and senior officer of ECT Aviation Support LLC, together with two other businesses connected to that network. Those allegations concerned the named persons and transactions, rather than Iranian civil aviation as a whole (U.S. Department of the Treasury, 2026).

Four further businesses were designated in connection with cargo or sales services. Treasury identified S Sistem and Mes Cargo in Türkiye, Icargo in Malaysia, and Tour Invest in Kazakhstan as companies that had arranged shipments or acted as general sales agents for Mahan Air. A general sales agent can connect an airline with freight customers and coordinate commercial arrangements, making such businesses relevant to an airline’s ability to sustain international services (U.S. Department of the Treasury, 2026).

Designation under either executive order carries blocking consequences within the reach of U.S. law. Property and interests in property of a designated person that are in the United States, or in the possession or control of a U.S. person, are blocked. U.S. persons are generally prohibited from engaging in transactions involving that property unless an exemption or authorization applies. OFAC’s ownership rule also treats an entity as blocked when one or more blocked persons own, directly or indirectly and individually or collectively, at least 50 percent of it (U.S. Department of the Treasury, 2026).

1.2 What General License DD actually permits

Alongside the designations, OFAC indefinitely suspended three provisions of the Iranian Transactions and Sanctions Regulations, 31 CFR Part 560, and Iran General License J-1. Two of the suspended provisions had narrow purposes that could be mistaken for general authorizations to service Iranian airlines abroad. Their terms provided no such blanket permission (OFAC, 2026, Iranian Transactions and Sanctions Regulations, 91 FR 57511).

Section 560.522 had authorized specified payments to Iran for government services connected with overflights of Iranian airspace or emergency landings by aircraft owned by U.S. persons or registered in the United States. Section 560.529 had permitted certain goods or services supplied in the United States to non-Iranian carriers transporting passengers or goods to or from Iran, including bunkering and emergency repairs, subject to its stated limits. Neither provision was a general license for a foreign airport to refuel every designated Iranian carrier (31 CFR §§ 560.522 and 560.529).

OFAC also suspended the licensing policy in section 560.528, which had addressed specific licenses for certain aircraft-safety transactions. A licensing policy governs how applications may be considered; it does not itself authorize every transaction within its subject matter. General License J-1, by contrast, had authorized the temporary reexportation to Iran of certain civil aircraft and related transactions. All four suspensions took effect on September 8 (OFAC, 2026, Iranian Transactions and Sanctions Regulations, 91 FR 57511).

General License DD provides a limited wind-down authorization for transactions previously permitted under sections 560.522 and 560.529 or General License J-1. It covers transactions prohibited by the Iranian Transactions and Sanctions Regulations only insofar as they are ordinarily incident and necessary to winding down those previously authorized activities. The authorization lasts through 12:01 a.m. Eastern Daylight Time on September 23, 2026. Any payment to a blocked person under the license must be made into a blocked, interest-bearing account in the United States in accordance with those regulations (OFAC, 2026, Iran General License DD).

The license does not restore the suspended permissions for continuing business. It also leaves other prohibitions in place: a transaction barred by another executive order or another part of OFAC’s regulations requires its own applicable exemption or authorization. General License DD cannot be treated as permission to deal with every airline designated under Executive Order 13902 or every business designated under Executive Order 13224 (OFAC, 2026, Iran General License DD).

OFAC issued a separate authorization under the Global Terrorism Sanctions Regulations, 31 CFR Part 594. Counter Terrorism General License 37 permits specified wind-down transactions involving ECT Aviation Support LLC, S Sistem, Mes Cargo, and entities covered by the license’s ownership provisions. It carries a September 23 deadline and requires payments to blocked persons under the authorization to be made into blocked, interest-bearing accounts in the United States. Its beneficiaries and regulatory basis differ from those of General License DD; it is not a general authorization to wind down dealings with every person designated on September 8 (OFAC, 2026, Counter Terrorism General License 37).

The remaining possibility of obtaining a specific license also changed. On September 10, OFAC announced that it would consider Iran-related specific-license applications under a presumption of denial, except where approval is required by law or in certain circumstances, such as risks to life, limb, or environmental safety. Such circumstances may justify consideration of an application, but they do not guarantee approval (OFAC, 2026, Licensing Policy Update under Operation Economic Outcast).

These authorizations concern transactions within the applicable U.S. sanctions framework. Their expiration does not instruct foreign aviation authorities to close airports or cancel traffic rights. A foreign supplier may nevertheless confront a separate risk of sanctions for particular dealings with a designated person. That risk depends on the authority governing the supplier’s conduct, not on the title or deadline of General License DD.

2. How Sanctions Can Interrupt International Flights

A scheduled international service depends on arrangements that extend well beyond the airline’s aircraft and crews. Fuel and ground services are commonly obtained at the destination airport, while ticket sales, cargo bookings, and payment processing may involve businesses in several countries. An airline can retain permission to operate a route yet encounter serious difficulties if those arrangements break down.

The September 8 designations affected both carriers and businesses that Treasury associated with Mahan Air’s commercial and procurement networks. They created direct restrictions where U.S. sanctions law applies and potential additional exposure for certain foreign dealings. These effects can alter suppliers’ decisions without any formal change to the route permission issued by the destination State (U.S. Department of the Treasury, 2026).

Bessent’s September 21 warning specifically identified fuel, landing services, and ticket sales. It does not establish that all providers had withdrawn by that date. Its practical significance lies in the dependence of international flights on businesses that must decide whether and on what terms they can continue serving designated carriers (CNBC, 2026, Squawk Box Interview with Scott Bessent).

2.1 Fuel, ground handling, and ticket sales

Refueling is an immediate operational concern. If an airport supplier declines to fuel an aircraft, the airline may have to revise its fuel planning, change its schedule, or cancel the intended service. The result depends on the aircraft’s capabilities, the route, the fuel available on arrival, and the feasibility of alternative arrangements. A refusal to refuel does not, without further evidence, establish that the destination government has prohibited the flight.

Ground handling can be equally consequential. Airlines may rely on local contractors for aircraft servicing, baggage and cargo handling, and other functions needed between arrival and departure. The loss of an essential contractor can interrupt operations at a particular airport even when the airport remains open and the airline still holds the relevant authorization.

Commercial disruption may develop less visibly. An agent that stops selling tickets can reduce an airline’s access to passengers in a particular market. Difficulties in receiving or transferring payments may affect its ability to maintain contracts, collect fares, or settle charges. Such problems can undermine a route over time without making an individual departure physically impossible.

Treasury’s September 8 action illustrates the commercial dimension of the restrictions. It designated companies that it identified as cargo-service providers or general sales agents for Mahan Air. The announcement did not designate every business supplying fuel, handling, ticketing, or payment services to every Iranian carrier. The exposure of any other provider requires its own legal and factual assessment (U.S. Department of the Treasury, 2026).

2.2 Different forms of exposure for foreign suppliers

A direct prohibition and the risk of a future designation are different legal constraints. U.S. persons generally cannot transact in property or interests in property of a blocked airline without an applicable exemption or authorization. Transactions within or passing through the United States may also fall within U.S. prohibitions. A supplier’s location abroad does not, by itself, establish either that the transaction is prohibited or that it is beyond the reach of U.S. law (U.S. Department of the Treasury, 2026).

Executive Order 13902 establishes several distinct grounds for designation. Section 1(a)(ii) addresses persons determined to have knowingly engaged in a significant transaction involving significant goods or services supplied or transferred to or from Iran for use in connection with a covered economic sector. Section 1(a)(iii) separately addresses material assistance or the provision of specified support, goods, or services to a person blocked under the order. Whether a foreign aviation supplier meets either ground depends on the relevant conduct and the conditions of that provision (Executive Order 13902, 2020, s. 1(a)).

The counterterrorism designations rest on a different authority. Executive Order 13224, as amended, provides grounds for designating persons who meet its specified support, ownership, control, or other criteria in relation to persons blocked under that order. Treasury’s September 8 designation of particular intermediaries and sales agents does not mean that every company performing a similar service has already been designated (Executive Order 13224, 2001, as amended; U.S. Department of the Treasury, 2026).

Foreign financial institutions face a further form of potential exposure under Executive Order 13902. Section 2 permits Treasury, following the required determination, to prohibit a foreign financial institution from opening a U.S. correspondent or payable-through account, or to prohibit or impose strict conditions on maintaining such an account. The provision applies where the institution knowingly conducts or facilitates a significant financial transaction for specified goods or services connected with a covered Iranian sector, or for or on behalf of a person blocked under section 1 of the order (Executive Order 13902, 2020, s. 2).

Those account restrictions differ from the blocking of an airline’s property and from designating a commercial service provider. Bessent’s warning about exclusion from the dollar system conveyed the financial consequences Washington intended foreign businesses to consider. It did not eliminate the need to identify the relevant legal authority and establish its conditions in an individual case (CNBC, 2026, Squawk Box Interview with Scott Bessent; Executive Order 13902, 2020).

A supplier may also withdraw for reasons that do not amount to a direct legal prohibition, including anticipated banking difficulties, insurance concerns, or a decision not to renew a contract. The fact that a flight was canceled after sanctions were imposed cannot alone establish which consideration caused the cancellation. Operational evidence and the governing legal measure are both needed to explain what happened.

3. Who Controls International Flight Rights?

Sanctions can affect an airline’s capacity to operate, but the legal permission to enter foreign airspace or provide a scheduled service comes from a different source. International civil aviation operates within a framework of territorial sovereignty, treaty rules, and permissions issued by the States concerned. An OFAC designation does not itself amend an authorization granted by a foreign aviation authority.

The Convention on International Civil Aviation, signed in Chicago in 1944, distinguishes the sovereignty of States over their airspace from the conditions governing scheduled and nonscheduled flights. It also addresses access to airports open to public use. These provisions establish neither an unrestricted entitlement for an airline to fly wherever it wishes nor authority for the United States to cancel flight permissions issued by another State (Convention on International Civil Aviation, 1944, arts. 1, 5, 6 and 15).

For a particular Iranian carrier, the relevant questions are concrete. Does it hold permission to operate the intended service? Has the State responsible for that permission imposed a restriction? Are the services required for the flight still available? Different answers can produce the same canceled departure, but they do not produce the same legal explanation.

3.1 Sovereignty and scheduled air services

Article 1 of the Chicago Convention recognizes the complete and exclusive sovereignty of each State over the airspace above its territory. A State consequently controls admission to its own airspace within the applicable legal framework. The provision gives the United States no corresponding power over the airspace of another State simply because Washington has sanctioned a carrier (Convention on International Civil Aviation, 1944, art. 1).

Scheduled international air services are governed more specifically by Article 6. Such a service cannot operate over or into a contracting State’s territory without that State’s special permission or other authorization, and it must comply with the terms of the permission granted. A history of flights to a destination does not establish that a carrier retains an unconditional right to continue the service (Convention on International Civil Aviation, 1944, art. 6).

Bilateral air services agreements and related authorizations may identify the airlines entitled to operate between particular States, the routes concerned, and the conditions attached to those services. Their legal effect depends on their actual terms. A conclusion that a specific Iranian airline has lost a treaty-based right, or that a foreign State has breached an agreement by restricting it, would require examination of the applicable instruments and decisions.

Article 5 treats aircraft not engaged in scheduled international air services differently. It provides specified rights concerning transit and non-traffic stops, subject to conditions and powers reserved to the territorial State. Nonscheduled carriage of passengers, cargo, or mail for remuneration or hire is subject to further conditions under that article. The permission requirement in Article 6 cannot be presented as the complete rule for every international flight (Convention on International Civil Aviation, 1944, arts. 5–6).

3.2 Airport access and operating conditions

Article 15 of the Chicago Convention concerns airports open to public use and specified air navigation facilities. Subject to Article 68, an airport that a contracting State makes available for public use by its national aircraft must be available under uniform conditions to aircraft of other contracting States. Article 15 also contains rules on charges for the use of airports and air navigation facilities (Convention on International Civil Aviation, 1944, art. 15).

That provision operates alongside the rules governing permission to provide an international air service. Article 68 allows a contracting State, subject to the Convention, to designate routes to be followed by international air services within its territory and the airports those services may use. Article 15 cannot, on its own, establish a carrier’s entitlement to begin or continue any scheduled route it chooses (Convention on International Civil Aviation, 1944, arts. 6, 15 and 68).

Airport access is also distinct from the purchase of commercial services. Article 15 does not guarantee that an airline can obtain fuel from a particular supplier, retain a ticketing agent, or require a ground-handling company to continue a contract. The legal position concerning those services depends on the provider, the applicable domestic rules, the contract, and any other relevant obligations.

An allegation of unequal treatment at an airport consequently requires an identifiable measure and a legal basis for assessing it. A refusal imposed by an airport authority may raise questions different from those arising when an independent supplier declines a commercial transaction. Disruption affecting an Iranian airline does not, without evidence of the conduct and the governing obligation, establish a breach of Article 15.

4. Decisions by States, Airports, and Private Companies

A foreign government may affect an airline’s operations by withholding or withdrawing a route authorization, restricting entry into its airspace, or imposing rules on airports within its territory. The legal basis for such action must be examined under the relevant domestic law and international obligations. A canceled flight, standing alone, does not demonstrate that the government issued an order or withdrew traffic rights.

Airport operators do not all have the same legal status. An operator may be a State organ, a body empowered to exercise governmental authority, or a commercially organized enterprise. Its status and the capacity in which it acted can affect whether its conduct is attributable to a State under international law. Public ownership alone does not settle that question (International Law Commission, 2001, arts. 4–5).

The International Law Commission’s 2001 Articles on Responsibility of States for Internationally Wrongful Acts distinguish conduct of State organs, conduct by entities exercising elements of governmental authority, and conduct carried out on a State’s instructions or under its direction or control. The articles are a text adopted by the Commission, not a treaty. Their provisions must be applied with regard to their content and the status of the relevant rules under international law (International Law Commission, 2001, arts. 4, 5 and 8).

Conduct attributable to a State is not automatically internationally wrongful. Article 2 identifies a further requirement: the conduct must constitute a breach of an international obligation of that State. Even if a decision by an airport operator can be attributed to its government, a finding of international responsibility requires identification of an applicable obligation and conduct inconsistent with it (International Law Commission, 2001, art. 2).

A private fuel supplier or sales agent may withdraw because a transaction falls within a direct prohibition, because it anticipates possible sanctions, or because it chooses not to continue a commercial relationship. None of those explanations can be assumed solely from the timing of a cancellation. Nor does a supplier’s response to U.S. pressure, without more, make its conduct attributable to Washington or to the State where it operates.

The distinction has practical consequences for assessing an interrupted route. An airline might retain permission to land but lose an essential handling contract. It might instead be unable to operate because the destination State has withdrawn its authorization. Both circumstances may result in a grounded aircraft; identifying the responsible decision and the applicable rule is what makes their legal consequences intelligible.

5. Reported Interruptions to Mahan Air Routes

Mahan Air’s suspension of services to Türkiye and Oman illustrates the operational disruption occurring after the September 8, 2026, sanctions announcement. Mahan Air was already subject to U.S. sanctions, but the new measures also targeted businesses that the Treasury Department associated with its aircraft procurement, cargo operations, and sales networks. The route suspensions followed those measures, although their timing alone does not establish why each decision was made (U.S. Department of the Treasury, 2026; Financial Times, 2026).

On September 16, Mahan Air announced that its flights between Tehran and Muscat would be canceled from September 17 until further notice. The airline attributed the suspension to an announcement by Omani aviation authorities. Its passenger notice establishes the routes affected, the effective date, and the explanation given by the carrier. It does not identify the Omani legal instrument or establish the precise reasons underlying the authorities’ decision (Mahan Air, 2026a; IranWire, 2026).

Mahan Air separately announced that its flights between Tehran and Istanbul and between Tehran and Ankara, in both directions, would be suspended from September 21 until further notice. It identified September 20 as the scheduled date of the final flights and attributed the suspensions to decisions by Turkish aviation authorities. The Financial Times independently reported the planned interruptions after reviewing notices sent to travel agencies (Mahan Air, 2026b; Financial Times, 2026).

There is evidence connecting the wider restrictions to U.S. diplomatic pressure. Reuters reported on September 18 that the Treasury Department had said Türkiye and Oman agreed to stop Mahan Air flights following discussions concerning compliance with U.S. measures. That statement provides an official U.S. explanation of the governments’ decisions. It does not establish the terms of the Turkish or Omani measures, or demonstrate that a particular sanctions provision directly required either State to suspend the routes (Reuters, 2026).

The distinction matters when identifying what actually interrupted the flights. An aviation authority’s restriction can prevent a carrier from operating a route even if fuel and handling services remain available. A supplier’s withdrawal may produce a similar result without changing the airline’s flight permission. Mahan Air’s notices attribute these suspensions to aviation authorities; they do not identify a fuel supplier, ground handler, or payment provider as the immediate cause.

The reported cancellations concern particular services operated by one airline. The Financial Times reported on September 17 that other Mahan Air routes and services offered by other Iranian carriers remained available at the time. That historical account limits what can be inferred from the three suspensions, but it does not establish the operational status of every route on September 22 or any later date (Financial Times, 2026).

6. Aviation Safety and the Limits of Service Restrictions

Restrictions on aviation services can create safety-related questions, particularly where aircraft operators require maintenance, replacement parts, or emergency assistance. The applicable rules depend on the service and the circumstances in which it is needed. A planned commercial departure, an aircraft in distress, and an application for permission to conduct a sanctions-restricted transaction do not engage identical legal obligations.

The September 8 measures are relevant because OFAC suspended provisions that had permitted certain aviation-related transactions or established a policy for considering aircraft-safety licenses. The changes narrowed permissions previously available under U.S. sanctions law. They did not eliminate the separate obligations of States under the Convention on International Civil Aviation (OFAC, 2026a; Convention on International Civil Aviation, 1944).

The existence of an operational interruption does not establish a safety emergency. A flight canceled before departure may cause substantial disruption without placing an aircraft in distress. Where an aircraft urgently needs assistance, however, its condition and location may bring additional legal rules into operation.

6.1 Aircraft in distress and emergency assistance

Article 25 of the Chicago Convention requires each contracting State to provide such assistance as it finds practicable to aircraft in distress within its territory. The State must also permit the aircraft’s owners or the authorities of its State of registry to provide assistance necessitated by the circumstances, subject to control by the territorial State’s authorities (Convention on International Civil Aviation, 1944, art. 25).

The obligation concerns assistance to an aircraft in distress. It does not confer an unrestricted entitlement to obtain fuel from any supplier for an ordinary scheduled service. An airline cannot establish an Article 25 violation merely by showing that a contractor refused to refuel an aircraft before a planned departure.

Where an aircraft is genuinely in distress, the relevant circumstances include its location, technical condition, immediate needs, and the assistance practicable for the territorial State. The Article 25 obligation must be examined separately from the question whether a particular payment, repair, or supply transaction falls within a U.S. sanctions prohibition or authorization. A sanctions designation alone does not establish that necessary emergency assistance has been withheld.

6.2 Licensing for safety-related transactions

Before September 8, section 560.529 of the Iranian Transactions and Sanctions Regulations authorized specified transactions involving goods and services supplied in the United States to non-Iranian carriers transporting passengers or goods to or from Iran. Those transactions included certain bunkering and emergency repairs. Section 560.528 served a different function: it established a policy for considering specific-license applications concerning certain aircraft-safety transactions (31 CFR §§ 560.528–560.529).

OFAC suspended both provisions effective September 8. It also suspended General License J-1, which had authorized the temporary reexportation of certain civil aircraft to Iran and related transactions. These measures affected different activities and beneficiaries. In particular, section 560.529 was not a general authorization for foreign suppliers to service every Iranian airline (OFAC, 2026a).

General License DD subsequently permitted specified transactions ordinarily incident and necessary to winding down activities previously authorized under section 560.529 or General License J-1, among other identified authorizations. Its deadline is 12:01 a.m. Eastern Daylight Time on September 23, 2026. The former aircraft-safety licensing policy in section 560.528 is not itself among the authorizations identified in General License DD (OFAC, 2026b).

The suspension of an authorization does not settle the legality of every transaction involving aviation safety. The answer depends on the parties, goods or services, jurisdictional connections, applicable prohibitions, and any separate exemption or authorization. A transaction does not become permissible under U.S. sanctions law solely because its intended purpose concerns aircraft safety.

OFAC further changed its approach to individual applications on September 10. It announced that Iran-related specific-license requests would be considered under a presumption of denial, except where approval is required by law or in certain circumstances, including risks to life, limb, or environmental safety. The policy allows such circumstances to be considered without guaranteeing that a license will be granted (OFAC, 2026c).

6.3 The ICJ’s 2018 civil aviation order

Civil aviation safety was addressed by the International Court of Justice in proceedings instituted by Iran against the United States on July 16, 2018. Iran alleged violations of the 1955 Treaty of Amity following the U.S. announcement on May 8, 2018, that it would reimpose sanctions. The proceedings concerned rights claimed under that treaty and measures associated with the 2018 announcement (Alleged Violations of the 1955 Treaty of Amity, Iran v. United States, Order of 3 October 2018).

When considering Iran’s request for provisional measures, the Court found that certain asserted treaty rights were plausible. It examined the risks associated with restrictions on goods and services necessary for civil aviation safety, including spare parts, maintenance, repairs, and inspections. Its assessment concerned the protection of claimed rights pending a decision on the merits; it was not a final finding that the challenged measures violated the treaty (ICJ, 2018, paras. 69–70 and 90–93).

On October 3, 2018, the Court unanimously ordered the United States, in accordance with its obligations under the Treaty of Amity, to remove impediments arising from the measures announced on May 8 to the free exportation to Iran of specified goods. These included spare parts, equipment, and associated services necessary for civil aviation safety. The Court also directed the United States to ensure that the relevant licenses, authorizations, payments, and transfers of funds were not restricted. It emphasized the binding character of provisional measures while making clear that its order did not prejudge the merits (ICJ, 2018, paras. 98–102).

The treaty’s subsequent termination limits the order’s relevance to new measures. On October 3, 2018, the United States gave written notice terminating the Treaty of Amity under Article XXIII(3), which provided for termination on one year’s notice. The treaty accordingly ceased to operate prospectively between the parties in October 2019. Its termination did not retrospectively remove the Court’s jurisdiction over the dispute instituted while the treaty was in force (Treaty of Amity, 1955, art. XXIII(3); ICJ, 2021, para. 24).

In its February 3, 2021, judgment on preliminary objections, the Court confirmed its jurisdiction to entertain Iran’s 2018 application. It also rejected the argument that measures concerning transactions with third countries necessarily fell outside the treaty’s subject matter. Those determinations concerned jurisdiction and admissibility. They did not decide whether the United States had breached the treaty, determine the legality of the September 2026 sanctions, or restore the treaty as a source of new substantive obligations after its termination (ICJ, 2021, paras. 61–84 and 114).

The 2018 order therefore remains relevant as an example of provisional judicial protection directed at aviation-safety goods and services under an identifiable treaty. Its treaty-specific basis, the subsequent termination of that treaty, and the different measures at issue in 2026 prevent it from being treated as a general civil-aviation exemption from sanctions or as a ruling on Iranian airlines’ present entitlement to operate abroad.

7. The Reach of U.S. Sanctions Beyond Its Territory

U.S. sanctions affect international aviation through more than one legal mechanism. Restrictions on U.S. persons, property within U.S. jurisdiction, and transactions conducted within or through the United States can directly prohibit particular dealings. A supplier established abroad may encounter those restrictions if the proposed transaction has a relevant U.S. jurisdictional connection. Its foreign location alone does not determine whether U.S. law applies.

Other measures seek to influence conduct taking place abroad by exposing persons or financial institutions to specified consequences. Executive Order 13902 establishes grounds for designating persons involved in certain transactions or support activities connected with covered sectors of the Iranian economy. It also provides for restrictions on U.S. correspondent and payable-through accounts of foreign financial institutions that meet the order’s conditions. Executive Order 13224, as amended, establishes separate designation grounds applicable to specified conduct involving persons blocked under its counterterrorism provisions (Executive Order 13902, 2020, ss. 1–2; Executive Order 13224, 2001, as amended).

These mechanisms can exert pressure on aviation businesses that are not themselves subject to an identical direct prohibition. A foreign airport contractor may be concerned about designation, the willingness of banks to process payments, or the reaction of other commercial partners. It may consequently stop serving a carrier before any sanction is imposed on the contractor. Such a withdrawal must be distinguished from conduct that U.S. law already prohibits.

U.S. domestic authorization does not, by itself, settle whether a particular measure complies with international law. That assessment may require consideration of the jurisdiction asserted, an applicable treaty, the operation of the measure, and any relevant obligations owed to another State. An objection by a foreign government likewise requires an identifiable legal basis before it can support a conclusion that an internationally wrongful act has occurred.

The distinction between economic pressure and control of flight permissions is especially important. The United States may impose restrictions within its jurisdiction and attach specified consequences to conduct abroad under its sanctions authorities. Article 6 of the Chicago Convention nevertheless leaves permission for a scheduled international service with the State whose territory the service seeks to enter or overfly. Washington’s designation of an airline does not itself exercise that State’s authority (Convention on International Civil Aviation, 1944, arts. 1 and 6).

8. What Would Establish a Worldwide Shutdown?

On September 21, Treasury Secretary Scott Bessent predicted that Iranian airlines would be shut down worldwide on September 23, 2026. The prediction concerns the practical outcome of U.S. sanctions pressure. Establishing whether it has occurred requires evidence of airline operations on and after that date, rather than reliance on the announcement of sanctions or the expiration of a general license (CNBC, 2026; OFAC, 2026b).

An individual canceled flight is not equivalent to a suspended route. An airline may cancel one departure while continuing its scheduled service on subsequent dates. A route suspension shows a broader interruption, but the airline may still operate to other destinations. Even the withdrawal of all services to one foreign country would not establish that the carrier had ceased international operations worldwide.

The announced Mahan Air suspensions to Muscat, Istanbul, and Ankara demonstrate interruptions to identified routes. Mahan Air attributed them to decisions by Omani and Turkish aviation authorities, while U.S. officials associated those governments’ decisions with discussions about sanctions compliance. Neither account establishes the cessation of every Mahan Air route or the international operations of all Iranian airlines (Mahan Air, 2026a, 2026b; Reuters, 2026).

A claim of worldwide cessation would require evidence covering the relevant carriers and their international services. Airline notices, airport departure and arrival information, and flight records may help establish whether a particular service operated. Each source has limits: a ticket offered for sale does not prove that an aircraft departed, while an absent flight-tracking record does not conclusively establish that a flight was canceled.

The distinction also matters when assessing the September 23 licensing deadline. General License DD concerns the wind-down of specified transactions previously authorized under U.S. sanctions regulations. Its expiration does not produce a comprehensive record of aircraft movements or establish that all foreign aviation authorities and suppliers have taken the same action (OFAC, 2026b).

As of September 22, the September 23 deadline had not yet arrived. The documented Mahan Air interruptions establish significant disruption to particular services, but the available evidence does not establish the predicted worldwide cessation. An assessment made after the deadline must be based on what the affected airlines, governments, airports, and service providers actually did.

Conclusion

The United States can impose sanctions on transactions within its jurisdiction and create substantial pressure on foreign businesses supporting Iranian aviation. Losing access to fuel, ground handling, ticket sales, or financial services may prevent an airline from operating a route even when it retains its aircraft and formal flight permissions. Those commercial consequences do not give Washington authority to close another State’s airspace or revoke that State’s operating authorizations.

Mahan Air’s announced suspensions to Türkiye and Oman show how the effects can be concentrated on particular destinations. The airline attributed the interruptions to foreign aviation authorities, while U.S. officials linked the governments’ decisions to discussions about sanctions compliance. The precise legal and operational mechanism behind each suspension must be distinguished from the broader sanctions policy. Safety-related transactions and assistance to an aircraft in distress raise additional questions governed by their own applicable rules.

Bessent’s September 23 prediction remains a claim about an anticipated outcome until supported by operational evidence. Whether Iranian airlines are grounded abroad depends on identifiable restrictions and decisions affecting particular services, together with verified information about flights that have actually ceased operating.

References

CNBC (2026) ‘CNBC transcript: U.S. Treasury Secretary Scott Bessent speaks with CNBC’s “Squawk Box” today’, 21 September [online]. Available at: https://pressroom.versantmedia.com/cnbc/press-releases/cnbc-transcript-us-treasury-secretary-scott-bessent-speaks-cnbcs-squawk-box-3