Russia's invasion of Ukraine has made Moscow turn to Iran.
Russian forces in Ukraine are using Iranian-made "kamikaze" drones that have already destroyed Ukrainian weaponry around the city of Kharkiv.
Iranian-made Shahed-136 drones seem to be used to compensate for Russian airpower that has proven ineffectual in combat and for Russian artillery that has concentrated far to the south of Kharkiv
A Ukrainian colonel in the Kharkiv region told The Wall Street Journal that the Russians have a lot of weaponry. They have started to use drones because they no longer have the advantage of the cannon.
It is not clear what impact the Iranian drones will have on the battlefield.
Samuel Bendett is an expert on Russian drones at the Center for Naval Analyses. They can hit Russian targets as well as stationary ones.
In the early days of the war, the Turkish-made Bayraktar attack drones, armed with anti-tank missiles, took a heavy toll on the Russian armor.
The TB-2 has a 39 foot wingspan and a maximum speed of 137 mph.
Iran's Shahed-136 and Russia's Shahed-131 are loitering missiles that are a cross between a drone and a missile, with a camera in their nose.
According to the Ukrainian military, the Shahed-136 has a cruising speed of 112 mph. Iran claims it has a range of more than 1,500 miles, which makes it bigger and faster than the US has supplied to Ukraine.
The Shahed-136's flaws were pointed out by western analysts.
The limitations of bargain-basement drones are jammable, small warheads of less than 50 pounds, and commercial components vulnerable to anti-drone microwave weapons.
The Shahed-136 is easy to shoot down for Ukraine.
"They are slow- and low-flying, which greatly limits their utility as responsive weapons against a sudden threat at range and also makes them comparatively easy to intercept with old-fashioned radar-laid anti-aircraft guns," he wrote.
The Shahed-136 is cheap and easy to operate, which could allow Russia to use swarm tactics that overwhelm a target with hordes of drones.
Russia's Shahed-136s are a problem for Ukraine. Damage to cities, bases and probably SAM radars will be caused by air defenses not intercepting them all. The delivery of short- and medium-range air defenses should be increased.
There is an emerging contest between Ukrainian air defenses and Iranian-made drones. "I think a lot will depend on whether Russian military can field them in large enough numbers to overwhelm Ukrainian air defenses," he said.
Why can't Russia field its own cheap loitering bombs? Is Iran going to supply Russia with a lot of drones?
Iran has emerged as a major player in the world of drones, which are relatively easy to develop and acquire compared to weapons like jets and tanks. Iran has sold drones to Venezuela for use in attacks on Saudi oil fields.
Russia and Iran have been in a marriage of convenience for a long time, with Iran buying Russian weapons like the S-300 anti-aircraft system, and Tehran may see support for Moscow as another way to counter the US.
With Iran still facing heavy international sanctions and facing increasing domestic unrest, picking a fight overUkraine seems risky. Russia and Iran may feel like they have nothing to lose.
His work has been published in Forbes, Defense News, Foreign Policy magazine, and other publications. He has a masters degree in political science. You can follow him on social networking sites.