Here’s what you’ll learn when you read this story:

• Russia has made the Shahed more dangerous by improving its stealth, navigation, and resistance to jamming, which could make future Iranian versions harder to stop.
• Shahed variants also increase the drone’s destructive potential against a number of targets, including air bases and buildings.
• The upgraded Shaheds appear to be a growing threat to U.S. forces in the Middle East.

On March 17, the U.S. Embassy in Baghdad lit up with explosions. A Shahed drone launched from Iran was the culprit. Two weeks earlier, the U.S. Embassy in Saudi Arabia suffered Shahed strikes, as did the Consulate in Dubai. These drones have also hit air bases, destroying parked U.S. aircraft and showing their incredible range and precision.

Russia, which initially imported Shaheds from Iran and now makes them under license, has extensively upgraded the design, says David Kirichenko, Research Fellow at the Henry Jackson Society. Instead of continuing to adopt Iran’s bewildering variety of attack drones, the country is trying to perfect just the Shahed.

Now, news reports confirm that Russia has shipped drone hardware to Iran.

“Russians did a relatively good job by concentrating on developing one platform, upgrading and getting feedback on Shaheds,” says Kirichenko. Those upgrades are likely to show up in the Middle East—where Iran’s Shaheds are likely to get significantly deadlier.

The basic Shahed-136 is a 440-pound drone with a seven-foot wingspan and a 50-horsepower piston engine, giving it a cruising speed of 120 mph. It flies like a WW1 aircraft, and is as easy to shoot down.

Shaheds rely on numbers: they are launched in waves, and while the vast majority are downed, some get through. Russia has focused on increasing the number that get through and on creating greater impact.

In 2023 Russia started launching black Shaheds, rather than the usual light gray. The paint contained particles of radar-absorbing carbon, making it a simple stealth coating, says Ukrainian Air Force spokesperson Yurii Ihnat. This makes it harder to spot on radar.

Kirichenko notes that Russia has also been making its drones harder to spot with thermal imaging.

“Measures to make Shahed less visible to radar and thermal sensors do not make them impossible to see, but they reduce the time for air defenses to detect and respond to them,” says Kirichenko.

Just a simple stealth coating could cut radar detection range in half, making interception challenging before the drones reach populated areas.

The original Shahed-136 has a 100-pound warhead comprising an explosive core in a metal casing—which becomes lethal shrapnel when the warhead detonates. “As the rate of interception went up, the Russians improved warheads so that if even a few got through, they would do significant damage,” says Kirichenko.

And the variations keep multiplying.

One upgraded Shahed has a precursor charge that can punch a hole through a concrete wall, and then detonate a main explosive charge inside a steel cone. This explodes inside fortified structures rather than just damaging the exterior.

Other versions add incendiaries such as chunks of magnesium-aluminum alloy, which burn at high temperature and start fires. There is also a pure incendiary version filled with a gelled petroleum mixture like napalm.

Yet another variant substitutes a thermobaric mixture for the high explosive. This forms a detonating cloud that has a much greater blast effect than standard explosive material, making it highly effective at destroying buildings.

A range of warheads would make Iranian Shaheds more effective against specific targets. So an incendiary warhead might be used to start a fire in a skyscraper; the penetrating version could hit hardened embassy buildings; and the thermobaric warhead might be used against an air base.

Shaheds rely on satellite navigation. When the Ukrainian version started jamming GPS, Russia added a powerful anti-jamming Kometa military-grade satellite navigation system; and as jamming technology continued to improve, Russia has repeatedly upgraded the Shahed with additional receivers known as Controlled Reception Pattern Antenna (CRPA), which can blank out jamming. “The Russians have increasingly been able to combine Kometa-family CRPA antennas with GNSS navigation, and we know the Iranians are using Kometa,” says Kirichenko.

The March attack on a British air base in Cyprus reportedly used a Shahed kamikaze drone with a Russian Kometa satnav.

Russia also added two-way communications to the Shahed using mobile phone SIMs or Starlink receivers. “In a drone war, connectivity is king,” says Kirichenko. These links mean that operators can watch the progress of their drones. If all the Shaheds in one area are getting shot down, other attacks can avoid it. If one drone gets through, they can send more down the same route.

Starlink satellite receivers provide broadband communication, enough to transmit video so operators can see the target. Russia has used these against moving targets, including passenger trains. While SpaceX blocked Russia from using Starlink, it’s still open to Iran—though it might not work for long. “You can bet that if Iranians used Starlink, within a few days SpaceX would rush to restrict their usage as they did with Russia,” says Kirichenko.

Because Shaheds are simple, low-speed aircraft that don’t need streamlined aerodynamics, Russia can attach a variety of payloads externally. In one version, the Shahed becomes a carrier for one or more first-person view attack drones. These are controlled via the cellphone network. Others are armed with missiles for air-to-air combat.

Both of these developments look impressive but have yet to yield results in Ukraine. “In terms of effects these experimentations have not yielded anything too significant,” says Kirichenko.

More concerning, some Russian Shaheds scatter small anti-personnel bomblets—small explosives that can kill over a wide area—as they dive on a target. Others drop larger anti-tank mines on roads along their route. Kirichenko says this would have much more impact in the Gulf States than in Ukraine, which has become hardened to Russia’s attacks.

“If Iran wants to conduct maximum destruction and wreak havoc on, say, Dubai, then dropping mines into the city drives the political outcome much more effectively than the Russians can in Ukraine,” says Kirichenko, “It gives Iran more of an asymmetrical benefit.”

Clearly Russia has a lot to offer Iran in terms of Shahed upgrades. Perhaps there will be action to prevent such technology transfer taking place, yet the current U.S. administration has been reluctant to tackle Russia head-on.

But the consequences could come in the form of significant U.S. casualties.