Secondary Sanctions and the Chilling Effect
The US Treasury's Office of Foreign Assets Control, or OFAC, rarely needs to name every Iranian airline. Secondary sanctions threaten any foreign bank, insurer, lessor, fuel supplier, or ground handler that does business with a designated carrier. That threat is enough. Turkish, Emirati, Qatari, and European companies stop selling Jet A-1 fuel, spare parts, ticketing services, and maintenance checks. Banks refuse to process payments. Even firms with no political stake in US-Iran tensions walk away. The result is not a clean diplomatic tool. It is a chilling effect that turns civilian transit into a casualty of a wider war by other means.
Washington and Jerusalem describe these measures as pressure on Tehran's nuclear program, ballistic missile exports, and regional proxies. The stated aim is to change government behaviour, not to ground families. Yet the lived reality for Iran's diaspora is a narrowing corridor. A student in Toronto cannot book a direct flight to Tehran. She flies to Istanbul, waits for a bus, crosses at Bazargan, and arrives two days later. If her father dies during that journey, she misses the funeral. Official strategy papers do not count that loss. Relatives do.
The Humanitarian Exception That Is Not
OFAC publishes exemptions for food and medicine. Aid groups repeat the phrase humanitarian exception. On paper, cancer drugs and infant formula are allowed. In practice, aviation is the supply chain that carries them. Radiopharmaceuticals for cancer imaging have half-lives measured in hours. Insulin and chemotherapy must move quickly and under controlled conditions. When cargo flights are cancelled, when insurers refuse to cover Iran-bound freight, when foreign banks will not touch a transaction, the exemption becomes a dead letter. The destruction of the aviation sector functions as a de facto blockade on medical imports without ever saying so.
Specialised equipment follows the same path. A hospital in Shiraz needs a replacement part for a linear accelerator. A transplant team needs a perfusion machine. An emergency physician needs to fly in for a complex procedure. These are not weapons. They are not dual-use in any meaningful sense. But they need a plane, a fuel stop, a payment channel, and an insurance policy. Sanctions do not have to ban them directly. They only have to make every intermediary afraid. The humanitarian exception survives in press releases while it dies at the airport counter.
An Aging Fleet and the Arithmetic of Risk
Iran Air, Mahan Air, and Aseman Airlines fly some of the oldest passenger jets in the world. The inventory includes Airbus A300s, A310s, Fokker 100s, MD-80s, and a handful of Boeing 747s kept alive by cannibalisation. Engines such as the CFM56 and the Pratt & Whitney JT8D need parts that cannot be legally imported. EASA and the FAA ban most Iranian carriers from their airspace. The fleet ages because new aircraft cannot be bought and old ones cannot be properly maintained. Passengers know this. They check tail numbers. They trade rumours about engine failures and runway overruns.
Safety is not the only cost. The psychological toll starts before the journey. A father in Isfahan weighs a domestic flight against a bus to Tehran, then a taxi to the border, then a 30-hour ride to Istanbul. He wonders whether the plane has a working weather radar. He wonders whether the bus will be stopped at a checkpoint in a Kurdish region. He wonders whether his visa will be honoured. The trip becomes an endurance test. For the sick, the elderly, and families with small children, the land route is not an alternative. It is attrition.
Overland Routes Through Unstable Border Regions
The main overland corridors run through Turkey, Armenia, Georgia, Iraq, and Oman. Tehran to Istanbul via Bazargan takes 30 to 36 hours by bus. Tehran to Yerevan via Nordooz takes 14 to 18 hours. Tehran to Baghdad via Mehran takes 12 hours when the border is calm. These routes cross areas shaped by Kurdish insurgencies, Armenian-Azerbaijani tensions, and remnants of ISIS. They are cheaper than flights but not safe. Women travelling alone report harassment. Families report extortion at informal checkpoints. Luggage is lost. Medicine spoils in the heat.
Regional airports once offered a middle path. Turkish Airlines, Emirates, and Qatar Airways connected Tehran to the world. Now they limit service, drop routes, or refuse Iranian passengers with certain documents. Oman has kept some flights, but even Muscat must weigh its banking ties to the US dollar system. The result is a patchwork of routes that changes month by month. Travellers rely on WhatsApp groups and travel agents who cannot guarantee anything. Aerial isolation does not stop movement. It forces movement onto roads where the state has less control and passengers have fewer rights.
Regional Compliance, Coercion, and Realignment
Turkey, Oman, the UAE, and Qatar are not simple participants in US policy. Turkey depends on Washington for F-16 upgrades, NATO coordination, and access to dollar clearing. The UAE and Qatar host major US military bases. Oman has long played mediator, but its banks still fear secondary sanctions. When OFAC designates an Iranian carrier, foreign airports do not have to agree with the policy. They only have to calculate the cost. A fuel contract with Iran Air is not worth losing correspondent banking in New York.
Security concerns matter too. Gulf states worry about Iranian drones, missiles, and proxy networks. Israel's campaign against Iranian assets has made airports and airlines into targets. Regional realignment after the Abraham Accords and the 2023 Saudi-Iran détente has not reversed the aviation squeeze. It has made it quieter. Countries that once allowed Iranian flights now cite technical reasons. They avoid the word sanctions. They do not want to be seen as enforcers. They also do not want to be cut off from the global financial system. Coercion works best when it looks like prudence.
Collective Punishment by Other Means
Iran's diaspora numbers in the millions. They live in Los Angeles, Toronto, Stockholm, Dubai, and London. They send money, call on holidays, and wait for visas. Aerial isolation severs the physical ties that hold families together. Grandparents meet grandchildren on screens. Weddings happen without siblings. Funerals happen without children. Students lose scholarships because they cannot return for interviews. Patients die waiting for medical evacuation. These are not collateral damage in a strategic game. They are the daily arithmetic of a policy that treats an entire population as leverage.
The Treasury argues that sanctions are reversible and targeted. The land routes tell a different story. They are long, expensive, and uncertain. They expose travellers to unsafe roads and corrupt checkpoints. They punish the sick, the young, and the old. They turn a two-hour flight into a two-day ordeal. Aviation is not a luxury for Iranians. It is a lifeline to medicine, work, education, and family. When that lifeline is cut, the consequences do not stay inside Iran. They travel overland, one exhausted passenger at a time.
