Iran’s confirmation that it was set to receive a batch of advanced Su-35 fighter jets from Russia has signaled the dawn of a new era in the complex relationship between Moscow and Tehran, whose burgeoning defense axis could have significant ramifications for the security interests of the United States and its allies in the Middle East.

The development, confirmed earlier this week by a member of Iran’s legislative National Security and Foreign Policy Commission, would mark the Islamic Republic’s first major acquisition of foreign warplanes this century. Set to arrive as early as this spring, the “fourth-generation ++” Su-35s would give the Iranian Air Force a substantial boost to its aging fleet, and set the stage for potential future exchanges of military equipment between the two powers.

Can Kasapoglu, a senior fellow at the Washington, D.C.-based Hudson Institute and directory of Security and Defense Research at the Centre for Economics and Foreign Policy Studies (EDAM) in Istanbul, Turkey, offered several reasons why “Iran’s Su-35 procurement is of particular importance.”

First, he argued that “such a super-maneuverable air-superiority fighter would boost Tehran’s control over the Iranian airspace.”

Russia’s United Aircraft Corporation chief Yury Slyusar has described the Su-35S—reportedly the model set to be transferred to Iran—as “unrivaled in aerial battles.” The aircraft was set to represent the finest of Russian warplanes available for export, but the war in Ukraine has complicated international arms deals for Russia, and the Su-35s in question were reportedly intended for sale to Egypt before the Arab country canceled.

At such an advanced level for a fourth-generation aircraft, the Su-35 is likely to stand out in the Middle East, where, as Kasapoglu pointed out, “except for Israel, no U.S. ally in the region flies with fifth-generation aircraft.” He described the Russian fighter as “a dangerous beast against 4th and even 4.5th generation Western aircraft, thanks to its kinematic edge.”

He also argued that “the Su-35 complicates any Israeli preventive action against Iran” at a time when the Israel Defense Forces (IDF) and their fifth-generation F-35 stealth fighters enjoy regionwide air superiority. In addition to conducting regular strikes against Iranian and Iran-aligned assets in Syria, the IDF has openly reserved the right to pursue an assault on the Islamic Republic itself and its nuclear program, which Iranian officials have insisted is purely for peaceful purposes.

While Kasapoglu said the F-35, “theoretically, would enjoy a strong beyond-visual-range (BVR) advantage over the Su-35 concerning the former’s information superiority and sensor superiority features,” he also said that if the state-of-the-art U.S. warplane “comes to within-visual-combat, which cannot be ruled out in a preventive strike scenario, the Su-35 might cause additional troubles.”

“Additionally,” he said, “lessons learned from Ukraine showed that the Su-35, equipped with beyond-visual-range missiles, can also make a potent combat-air patrol (CAP) asset, thanks to its powerful Irbis-E radar.”

Russia, Sukhoi, Su-35S, conducts, combat, in, Ukraine
A Russian Sukhoi Su-35S fighter jet conducts what the Russian Defense Ministry described as “combat action” as part of the “special military operation” against Ukraine in this still from a clip published on January 11. Iran has confirmed it was set to receive a number of Su-35s in what could prove to be the most significant update and improvement to the country’s aerial capabilities since the 1979 Islamic Revolution overthrew a monarchy backed by the West.
Russian Ministry of Defense

In addition to the Su-35, other Russian assets identified by Kasapoglu that would significantly enhance Iranian capabilities include “ramjet-empowered, sea-skimming super-sonic anti-ship cruise missiles” like the Oniks and Yakhnot missiles fielded by Russia’s Bastion-P system, as well as the the advanced S-400 surface-to-air missile system, which Russian officials have repeatedly stated they were willing to sell to the Islamic Republic.

Guy Plopsky, an Israeli defense analyst, told Newsweek that “Iran’s acquisition of Su-35 fighters and S-400 systems would pose a significant challenge for Israel’s 4th-gen aircraft,” specifically ‘its F-16 and F-15 fleets.”

And while he argued that “Israel’s continued acquisition of the F-35I ensure it retains superiority in the region,” he emphasized that “it is important” the Israeli Air Force expand this fleet and also consider “expanding its stand-off precision-strike capabilities” in order to keep up with with an evolving threat environment.

Former Israeli officials have also previously expressed to Newsweek concern regarding the potential long-term strategic consequences of the other side of the growing Russia-Iran defense partnership.

Iran’s procurement of Su-35 aircraft came to light only months after reports emerged of Russia acquiring loitering munitions, sometimes referred to as “kamikaze” or “suicide” drones, such as the Shahed-131 and Shahed-136 that have since seen action to devastating effect in Ukraine.

Though Iranian officials have acknowledged sending drones to Russia as part of pre-existing agreements forged prior to the war, Tehran has not come out in explicit support of Moscow’s campaign in Ukraine. Iranian officials have portrayed their country’s acquisition of Russian weapons as a natural development in Tehran’s quest to update its air power.

“Due to the lack of warplane purchases from any country since Iran’s Islamic Revolution in 1979, Iran’s air capability has become outdated,” the Iranian Permanent Mission to the United Nations told Newsweek.

The mission pointed out that, “for years, Iran sought to purchase warplanes from western and eastern countries,” but under United Nations Security Council 2231, “Iran was banned from buying or selling conventional weapons, until October 2020.” That was when U.S. efforts to reinstate the decade-long embargo failed in the face of backlash over Washington’s exit from a multilateral 2015 nuclear deal known as the Joint Comprehensive Plan of Action (JCPOA).

“Iran restarted its efforts after the ban was lifted, and Russia replied positively,” the mission said. “Iran’s goal is to rebuild and strengthen its air defense capability, which is defensive in nature and not offensive, and we don’t assess any threats from our neighbors.”

Anton Mardasov, a scholar at both the Washington, D.C.-based Middle East Institute and the Moscow-based Russian International Affairs Council (RIAC), told Newsweek that, “undoubtedly, the Su-35s will strengthen Iran’s air fleet,” but also noted a significant improvement may require a much more ambitious project. He described the overall state of Iran’s air power as being “in a terrible state,” still based largely on platforms acquired during the days of Iran’s pre-revolutionary monarchy.

“It relies on American F-5 and F-14 fighters purchased during the Shah, on Soviet fighters and their Chinese copies, as well as on allegedly Iranian military industrial products, which are in fact upgraded copies of 40-year-old American aircraft,” Mardasov said. “It’s clear these aircrafts can’t stand up to Israeli or, for example, Saudi aircrafts on the technical level.”

He also noted that it was this vulnerability that prompted Iran to invest in the drone and missile programs that have drawn Moscow’s interest.

“In this respect the Su-35s will increase combat effectiveness and, of course, provide a long-term reserve for the training of Iranian pilots in the use of more modern equipment and opportunities for copying and more profound modernization of aviation in general,” Mardasov said.

While he argued that the longevity of Iran and Russia’s alignment in the defense sphere remains to be proven, given the backlash Tehran has received over its indirect role in the Ukraine conflict, as well as Moscow’s own defensive needs to continue waging its war, he noted that “Iran and Russia have recently had deeper cooperation on the military side than it seemed at first sight,” to include radar supplies, satellite contracts and more.

“So far I’d regard the rise in Iran-Russia relations as a classic short-squeeze, to put it in stock market terms,” he noted. “But sharp steps towards rapprochement are possible, especially since the U.S.-Iran negotiations on the JCPOA have collapsed.”

Russia, Shoigu, Iran, Bagheri, meet, in, Moscow
Iranian Armed Forces Chief of Staff IRGC Major General Mohammed Bagheri and Russian Defense Minister Sergei Shoigu hold talks alongside their respective teams during a meeting in Moscow on October 19, 2021. The two countries have cooperated closely in support of a common ally in Syria, and continue to expand military-technical relations despite Western sanctions.
Russian Ministry of Defense

The divergence of Iranian and Russian interests has introduced some controversy into their relationship. The two countries have long experienced extended periods of ups and downs in their bilateral dynamic, and mutual suspicions persist despite the recent uptick in collaboration.

One Iranian security expert, who requested anonymity due to the sensitive nature of the subject, told Newsweek that the Su-35s may “encounter delays” due to “the status quo of the relationship between Tehran and Moscow, which does not sound so good.”

“There is a big ‘if’ here,” the Iranian expert said, “and Russia has rarely kept its promises to Iran.”

But despite these difficulties, the Iranian expert argued that “the relationship between Iran and Russia regarding defense cooperation is separate from that of diplomatic relations.” The expert pointed out that this is due, at least in part, to the fact that Iran’s defense cooperation was being headed by Major General Mohammed Bagheri, an Islamic Revolutionary Guard commander who serves in the seniormost position of chief of staff of the entire Iranian armed forces.

“I think, regardless of whatever happens in the diplomatic scene between Tehran and Moscow,” the expert said, “it is safe to assume the two countries will continue to develop their defense cooperation.”

Igor Matveev, an RIAC expert who is a senior research fellow at the Russian Academy of Sciences’ Institute of Oriental Studies and a lecturer at the Moscow State Institute of International Relations (MGIMO), also views recent developments between Iran and Russia as rooted in a far deeper trend.

“Both sides have been building such partnership for more than a decade,” Matveev told Newsweek. “It includes a permanent dialogue between the leaderships of Russia and Iran, a trilateral format (with Turkey) on Syria, coordination on the ground in Syria, and also the Russian-Iranian trade and economic cooperation.”

“However,” he added, “the successful improvements in the mil-tech cooperation could contribute to enhancement of mutual trust between Moscow and Tehran.”

Iran and Russia’s joint support for Syrian President Bashar al-Assad marked another major milestone for the relationship between the two nations. With support from Russia in the sky and from Iran and its allied militias on the ground, the Syrian government managed to turn the tide of its civil war and regain most of the country from rebels and jihadis, despite active Western opposition to the Syrian leader.

And while Syria remains a volatile battleground for foreign powers including Russia, Iran, and Turkey, along with the U.S. and Israel, Matveev argued that boosting Moscow and Tehran’s defense ties will “not lead to escalation of confrontation in the Middle East, since each country has a legitimate right to self-defense.”

Rather, he argued that “the fact that there is mil-tech cooperation between Russia and Iran illustrates that Russia has been returning to the Middle East.” He also noted that “our mil-tech cooperation in the MENA region does not encompass Iran only,” and that “we are open to cooperation with other regional players like the Gulf countries and Turkey,” which already defied U.S. sanctions to receive the S-400 as part of a 2017 deal that withstood immense pressure from Washington in recent years.

While, as Matveev pointed out, the U.S. and European countries regularly supply arms to partners across the globe, including the Middle East, President Joe Biden‘s administration has sharply criticized the defense partnership between Iran and Russia, especially in the context of the war in Ukraine, which is currently among the leading recipients of Western weapons.

Drone, resembling, Iran, Shahed, 136, hits, Ukraine
An unmanned aerial system resembling an Iranian Shahed-136 loitering munition is seen flying over Kyiv during a barrage of drone attacks on Kyiv on October 17. Iran has denied deliberately backing Russia’s war effort in Ukraine and has proposed a joint Iranian-Ukrainian experts’ committee to investigate the matter.

But Russian platforms in Iranian hands could also prove a challenge for U.S. forces in the Middle East, as tensions between Tehran and Washington remain high with JCPOA diplomacy indefinitely on hold. Like Israel, the U.S. has warned that “all options are on the table” in terms of dealing with Iran and its nuclear program.

Speaking to reporters earlier this month, White House National Security Council Strategic Communications Coordinator John Kirby made reference to what he described as a “deepening, burgeoning defense relationship between Iran and Russia.”

“It’s concerning to us not only because of the war in Ukraine,” Kirby said at the time, “but what it could mean in terms of our national security interest in the Middle East and those of our partners there.”

Reached for comment by Newsweek, U.S. Central Command (CENTCOM) spokesperson Major John Moore expressed confidence that the U.S. military would continue to be able to deal with regional adversaries.

“CENTCOM and our partners are well-equipped to mitigate threats to the region,” Moore said. “CENTCOM and its partners regularly conduct exercises and training events, some of which are focused on air defense/offense, from both the air and ground.”

And while he said he “won’t speak to the specifics of all capability increases across CENTCOM” in relation to Iran acquiring advanced Russian weaponry, he asserted that U.S. forces were “postured to defend against any regional threat.”

Su-35s alone may not change this dynamic, but a major shift in Iran and Russia’s view of one another and the future results of this partnership may prove to be a longer-term issue for the U.S. and its allies.

Abdolrasool Divsallar, a professor at Università Cattolica del Sacro Cuore’s Higher School of Economics and International Relations (AZERI) in Milan, Italy, and a scholar with the Middle East Institute’s Iran Program in Washington, D.C., argued that the biggest change in the dynamic between the two powers was the emergence of an “interdependency of security.”

“I think Moscow and Tehran are working on a very broad concept of regime security,” Divsallar told Newsweek. “This means that both sides have realized that, through resisting the U.S. pressure and the Western pressure, they need each other, and that’s the new reality of the time.”

This new mutual understanding, as seen by Divsallar, “means that cooperation will not be limited to military and security sphere” and may further extend to the realm of economics and trade, including potential deals on the agricultural and banking sectors. Iran and Russia have already begun intensify their cooperation on these fronts.

He argued that just as Tehran has come to realize the increasingly remote possibility of reviving the JCPOA and revitalizing trade with the West, Moscow has come to terms with the diminishing chances of improving its own relationship with Washington and its allies.

Given this shift, he said that, even at a time when Russia is bolstering its relationship with Iranian rivals such as Saudi Arabia and the United Arab Emirates, Moscow will continue to press past the limits of a previous more cautious approach to Tehran.

And should Israel or the U.S. seek to escalate action against their mutual adversary, Divsallar argued that Russia is more likely than ever to step in, raising the stakes of intervention.

“What I assume is that as the threats of a possible military strike against Iran will increase,” Divsallar said, “Russia will also try to help Iran in order to improve its defensive capability in order to prevent such a scenario.”

Newsweek has reached out to the Israel Defense Forces and Russian Foreign Ministry for comment.