Istanbul Went Quiet, Guangzhou Didn't

On September 8, the United States Treasury announced it was sanctioning every one of Iran's remaining airlines. In the same release, Treasury said one of those airlines, Mahan Air, received at least three Boeing 777s in the summer of 2026. Sanctioned on paper, and still taking delivery of jets. The sweep covered 36 targets in Iran's aviation business, 27 of them airlines. Treasury Secretary Scott Bessent attached a warning to "anyone doing business with Iran's remaining airlines, all of which we sanctioned today: You are at risk of being cut off from the global financial system."

Mahan is based in Tehran. Washington first sanctioned it in 2011, and it kept flying anyway. On September 21, Bessent went on television and put a date on this new push: "On September 23rd, all the Iranian airlines, all the Iranian airlines will be shut down around the world." By that Wednesday, Mahan's flights to Turkey and Oman had stopped. But at 4:39 that afternoon, local time, flight-tracking data showed Mahan flight IRM093 from Tehran landing in Guangzhou, in southern China.

So what, if anything, is different this time? We'll start in 2011 and with those three jets, to see why sanctions never grounded Mahan. Then the new lever Bessent aimed at whoever stands at the far end of each route. Then deadline day, from Istanbul, where Mahan said the Turkish government asked it to stop, to a tracked landing in Guangzhou and ticket sales in Shanghai.

The chase has a start date. On October 12, 2011, Treasury designated Mahan Air, saying it supported the Qods Force of Iran's Revolutionary Guard. Fifteen years on, the planes are still going. The aviation website MiGFlug says Mahan has been flying into Chinese airports for years, and Singapore's Straits Times, reporting with the French news agency AFP, says Iranian airlines fly regular direct routes to Beijing, Shanghai and Guangzhou. Blacklisted in Washington, welcome in China.

Then there are those three 777s. As Treasury tells it, each jet came out of a retired fleet and passed through a company in the United Arab Emirates, ECT Aviation Support, where it picked up temporary registrations. The planes were diverted through the Emirates and Oman, with that firm and a Turkish company, Sky Phoenix, acting as intermediaries. And Treasury said the route closely mirrored earlier sanctions-evasion operations for Mahan. You almost have to admire the persistence.

Almost. Treasury's case is heavier: it says Iran's government uses its aviation sector to move weapons, personnel and illicit cargo, and it accuses another Turkish firm, S Sistem, of coordinating shipments for Mahan that included drone components. The September 8 action, Treasury said, also sanctioned companies it accused of continuing to support Mahan.

That action was part of something larger. On August 24, Bessent announced that Treasury had begun what it calls Operation Economic Outcast, with aviation among its targets. His stated goal: "Our objective is to sever every economic lifeline that sustains this tyrannical regime until Tehran stands alone." And then: "We are enforcing a zero-leakage approach." Zero leakage, aimed at an airline that has leaked through for fifteen years.

So how do you ground a plane you can't touch? On the business network CNBC, Bessent spelled it out: "If they land, you cannot provide them with fuel, you cannot provide them with landing services, you cannot sell them tickets or you will be knocked out of the dollar system."

That's the shift. The target is no longer just Mahan and its named helpers. It's the fuel supplier, the ground handler, the ticket seller. Experts told the Qatar-based network Al Jazeera that America can't shut foreign airspace to Iranian carriers; it can punish the businesses that serve them. Or, as Bessent put it: "We know who they are, they know who they are, and we are putting a stop to it."

Saj Ahmad, chief analyst at StrategicAero Research, saw the catch: "Getting all these pieces of the puzzle to do what the US demands is tricky."

By then, the far ends of the routes were already moving. Mahan's notices start with Oman. In an English translation, its statement read: "According to the announcement by the aviation authorities of the Sultanate of Oman, Mahan Air flights on the Tehran–Muscat–Tehran route will be canceled starting from September 17 until further notice."

Then Turkey. Mahan's own notice listed its last Tehran–Istanbul and Tehran–Ankara flights for September 20, with service suspended from the 21st, and Mahan said the Turkish government had asked it to stop. Reports differ on exactly when the Turkish flights stopped and in what order. The Financial Times reported the suspensions came as sanctions reached ground-service and sales networks.

Istanbul. A city Mahan was still reaching before the suspension, gone quiet. And it spread. Iraq announced on the evening of September 21 that it was suspending flights by sanctioned Iranian airlines. Georgia barred Iranian carriers. Azerbaijan suspended their flights. On deadline day, a travel agent in Tehran told AFP that flights to Baghdad, Muscat, Qatar, Georgia and Azerbaijan had all been suspended. This time, the people at the other end acted.

Closed routes have passengers. Al Jazeera reported that nearly 7.2 million international travelers flew with Iranian carriers in 2025. The economist Nader Habibi told the network, "The airline prices are already increasing, and the increase in the recent couple of weeks has been substantial," up to 100 percent in some cases. Iran Air's chief executive, Taher Abdolhai, told the Iranian news site SehatKhabar the pressure was spreading "like metastasising cancer." And Ahmad warned such disruptions could immediately ground a third of Iran's operational fleet.

Then came the afternoon of September 23. At 4:39 p.m. local time, the tracking site FlightRadar24 showed IRM093, out of Tehran, touching down at Guangzhou Baiyun airport. And the same Tehran travel agent who listed the suspensions told AFP that routes to several other destinations remained available, China among them.

One detail doesn't fit. The flight wasn't listed on the airport's own official website. Istanbul dark, Guangzhou still receiving. The chase Washington began in 2011, pushed farther east.

Unless Beijing is next. On CNBC, Bessent said: "And the Chinese financial authorities, including Governor Pan at the PBOC, have been very engaged in the process." That's Pan Gongsheng, governor of the People's Bank of China. China's foreign ministry spokesman, Guo Jiakun, sounded different: "China consistently opposes illegal unilateral sanctions that lack a basis in international law or authorisation from the UN Security Council." A central bank Bessent calls engaged, a foreign ministry that objects. Day one doesn't settle which voice wins.

That same morning, AFP visited Mahan Air's office in Shanghai. Staff there said no notice of cancellations had come. Tickets for the coming week were being sold as normal. Deadline day, and Shanghai was booking next week.

The announced mechanism is pressure on foreign service providers to stop serving the airline. Someone at the other end has to act. In Turkey, Mahan said, the government asked, and the flights stopped. In Shanghai, staff said no cancellation notice had come. Which makes Bessent's line sound different now: "We know who they are, they know who they are." Less a threat to Mahan than a message to the staff in that Shanghai office.