Russia's Sukhoi Su-35 Fighter Jets Deal Isn't A Silver Bullet For Iran's Battered Air Defenses

Iran is acquiring Russia's Su-35 fighter jet, a top Iranian military official said.

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• Iran looks to finally be getting the Su-35 fighters it has long sought.
• New and well-armed Su-35s won't replace the capabilities of Iran's degraded air defenses.
• The Su-35 is a jolt for Iran's airpower, especially if it comes with a beyond-visual-range missile.

Iran may finally get the advanced Russian fighter jets it has sought for years, but analysts are skeptical that a few dozen Su-35 Flankers will make up for the damage Israel recently inflicted on Iran's air defenses.

Ali Shadmani, a senior commander in Iran's powerful Islamic Revolutionary Guard Corps paramilitary, confirmed the Su-35 order on January 27. Iranian state-run media have repeatedly reported imminent deliveries of these 4.5-generation Russian jets in recent years, which have invariably proven premature or downright false but there's reason to believe they're finally going through. Shadmani's statement did not reveal how many Su-35 Flankers Tehran ordered or when it expects deliveries in what's seen as a quid pro quo for the Iranian Shahed attack drones Russia has used in the thousands against Ukraine since 2022.

Iran's aging air force has long needed newer aircraft and the Su-35 brings significant capabilities to threaten enemy aircraft near Iranian airspace. But Arash Azizi, senior lecturer in history and political science at Clemson University, believes even an imminent delivery of Su-35s would still be "a case of too little, too late" for Tehran.

"This is still a meaningful upgrade for Iran's beleaguered air force and one that it has waited for for a long time," Azizi told Business Insider. "But it doesn't do much to fill the gaps that Iran will have against adversaries such as Israel."

"It will be a drop in the bucket."

Previous reports suggested Iran would receive at least 24 Flankers originally built for Egypt or up to 50 Su-35s ordered and paid for under a previous presidential administration.

IRGC commander Shadmani's remarks come two weeks after Iran and Russia signed a 20-year strategic partnership and in the wake of a devastating Israeli air and drone campaign that destroyed most of Iran's strategic, long-range S-300 air defense systems.

A timely delivery of these jets — possible but far from certain — could enhance Iran's "overall defensive and deterrent" capabilities, said Freddy Khoueiry, a global security analyst for the Middle East and North Africa at the risk intelligence company RANE. Their delivery could also make Israel "cognizant of the threat of advanced fighters" in Iranian hands.

Iran's current fighter fleet is badly outdated compared to most of its neighbors in the Middle East. It consists of F-14A Tomcats and F-4 Phantom IIs from the pre-1979 rule of the last shah, when Tehran was an American ally. Tehran's only notable fighter acquisitions since were a fleet of MiG-29 Fulcrums from the Soviet Union in 1990. Tehran also confiscated Iraqi aircraft, including French-made Mirage F1s, flown to Iran to evade destruction in the 1991 Persian Gulf War.

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While factory-fresh Su-35s would be Iran's most significant fighter acquisition in a generation, they won't replace the capabilities of Iran's degraded air defenses. For example, Khoueiry noted they could not "directly replace the persistence coverage, area denial, and wide-area protection" offered by ground-based systems like the Russian-made S-300.

"Iran would also need time to train crews and integrate the Su-35 into its existing network of sensors, command-and-control nodes, and other defensive assets," Khoueiry told BI.

"While modern fighters can deter hostile operations and bolster interception capabilities, they work most effectively when combined with robust surface-to-air defenses," Khoueiry said. "Therefore, replacing lost S-300 systems remains crucial for any comprehensive and layered Iranian air defense strategy."

Federico Borsari, a defense expert at the Centre for European Policy Analysis, believes the Su-35 will significantly improve Iran's air defense and offensive capabilities.

At the same time, he anticipates that Iran will try to acquire the more advanced Russian S-400 to replace the S-300s it lost.

"However, it's not clear how long it might take to create a highly layered air defense network," Borsari said. "Likewise, it will take a few years for Iran to get a fully operational squadron of Su-35s (time for training, infrastructure adaptation, integration of the system in the doctrine and concept of operations, etc)."

"So, Israel retains an important advantage for the time being."

The Su-35 is a significant jolt for Iran's airpower. Borsari noted the aircraft's significant maneuverability provided by its Saturn AL-41FS turbofan engines. These engines give the jet a high climb rate, acceleration, and "superior kinematics performance," even at speeds up to Mach 2.25. And its Irbis-E radar can simultaneously scan the ground and air over a wide area.

"As a whole, the capabilities of the Su-35, in particular the combination of the Irbis-E radar and beyond visual range R-77-1 missiles with active radar guidance, would definitely improve the Iran air deterrent's combat air patrol capabilities and make it much more dangerous for Western fourth and even 4.5-generation aircraft, including Israeli F-16s and F-15s," Borsari told BI.

It's possible that Russia will also deliver the R-77-1 missiles to powerfully arm the Su-35. Moscow similarly provided beyond-visual-range air-to-air missiles with the MiG-29A fighters it provided Tehran in the early 1990s.

While it remains "inferior from a technical standpoint" to Israel's stealthy fifth-generation F-35I jets, Borsari said, the Su-35 could still pose dangers to the premier Israeli aircraft — some of which likely entered Iranian airspace during the October 26 strikes.

"The Su-35 can become a threat by both using long-range R-77-1 air-to-air missiles or by getting within visual range and employing its better air-superiority characteristics against the F-35."

"Against this backdrop, Israel will do its best to avoid [within visual range] engagements and use the F-35 in its comfort zone."

It's likely that future Israeli strikes, should they come, could use F-35 stealth fighters to target Su-35s on the tarmac, not unlike how they struck air defenses in October. Israel may again use its standoff air-launched ballistic missiles to destroy these aircraft from a distance.

"With Israel having demonstrated its advanced stealth capabilities in the past year with its effective attacks against the Iranians, there is a decent chance the Israelis could launch a preemptive attack that at least grounds a portion of these Russian-built fighters and prevents the Iranians from effectively using them," RANE's Khoueiry said.

Paul Iddon is a freelance journalist and columnist who writes about Middle East developments, military affairs, politics, and history. His articles have appeared in a variety of publications focused on the region.