Can a Su-35 Delivery Turn the Tide in Iran’s Favour? How Russia Jets Already on Order Can Transform Air Defence Ops.

Following Isreal’s initiation of air strikes against a wide range of Iranian military, infrastructure and political targets on June 13, and Iran’s launch of retaliatory missile strikes later that day, the Israel Defence Forces have continued to receive a range of support from across the Western world. The United States has <a href="https://militarywatchmagazine.com/article/how-effective-is-thaad-in-defending-israel-against-iranian-missile-strikes" target="_blank">actively employed</a> ground based and maritime air defence systems to attempt to blunt Iran’s retaliatory strikes on Israel, and having bolstered Israel’s arms inventories for several months, is expected to resupply its forces if necessary. The United Kingdom has meanwhile deployed fighter aircraft to the Middle East to provide greater protection against Iranian drone strikes, while a number of unconfirmed reports indicate that NATO members including Germany are providing aerial refuelling support to allow Israeli fighter aircraft to reach Iranian targets. Iran, by contrast, lacks foreign support, with the <a href="https://militarywatchmagazine.com/article/netanyahu-details-israeli-air-turkish-takeover" target="_blank">fall of Syria</a> to Turkish and <a href="https://www.timesofisrael.com/idf-chief-acknowledges-long-claimed-weapons-supply-to-syrian-rebels/" target="_blank">Israeli backed insurgents</a> in December 2024 having left it isolated in the region, while its primary supplier of ballistic missiles North Korea is not well equipped to make major new equipment deliveries in wartime.<img src="https://militarywatchmagazine.com/m/articles/2025/06/14/article_684e0462800ec1_50691911.png" title="Israeli F-35s and F-15s Refuel in the Air During Simulated Attack on Iran">As Western support for Israel’s ongoing war effort is expected to continue to escalate, Russia’s strong condemnation of Israeli attacks has raised the possibility that Moscow could intervene in the conflict by bolstering Iran’s air defences. Although Russia’s own ground-based air defences are heavily committed to countering NATO and Ukrainian forces across multiple fronts, the country’s fighter inventory is far less stretched, while it <a href="https://militarywatchmagazine.com/article/iran-confirms-order-finalised-su35-fighters" target="_blank">has been confirmed</a> that Iran has placed orders for new Su-35 fighter planes. With Iranian pilots having been reported since 2022 to be training in Russia, while satellite images have confirmed that Iranian bases have <a href="https://militarywatchmagazine.com/article/new-airbase-iran-su35-air-defence" target="_blank">long been prepared </a>to host the aircraft, there is a significant possibility that should the war continue, Su-35s may be delivered to the Iranian Air Force. With the obsolescence of the Iranian fighter fleet having been a <a href="https://militarywatchmagazine.com/article/poor-deterrent-iran-fleet-300-fighters-equipped-stop-israel" target="_blank">primary factor </a>in the favour of its adversaries, the supply of Su-35s could significant shift the balance of power in the theatre.&nbsp;<img src="https://militarywatchmagazine.com/m/articles/2025/06/14/article_684e03e7c352b0_97392472.jpeg" title="Russian Air Force Su-35 Fires R-37M Air-to-Air Missile">Although the number of Su-35s thought to have been ordered would comprise only a small fraction of the Iranian fleet, likely around 10 percent, the fighters’ effect could be disproportionate. The Su-35 is <a href="https://militarywatchmagazine.com/article/ukrainian-air-force-f16s-far-outmatched-russian-fighters" target="_blank">significantly more capable</a> than the F-15s and F-16s operated by the Israeli Air Force, which have not been modernised to a ‘4+ generation’ standard, and have been restricted to operating outside Iranian airspace to launch missile attacks from safe distances. The F-35s which have <a href="https://militarywatchmagazine.com/article/two-israeli-f35-shot-down-iran-pilot-captured" target="_blank">penetrated Iranian airspace</a> are limited to carrying only a small payload two air-to-air missiles each due to their stealth configuration and the allocation of internal weapons bay space to gravity bombs. Su-35s could thus be deployed both to harass F-15s or F-16s at long range, or even to attempt to neutralise them with long range missile strikes, and potentially to engage F-35s inside its airspace.Even in limited numbers, Su-35s could prove invaluable serving as elevated sensors, using their very large<a href="https://militarywatchmagazine.com/article/why-russia-s-air-force-loves-the-su-35-s-irbis-e-radar-a-detailed-look-at-the-sensor-suite-built-to-hunt-stealth-fighters" target="_blank"> Irbis-E phased array radars</a> and complementary <a href="https://militarywatchmagazine.com/article/su35-triple-radars-detect-stealth" target="_blank">L-band AESA radars</a> to support ground-based air defence systems in engaging the stealthy F-35s that do enter Iranian airspace. If equipped with R-37M air-to-air missiles, which far outrange the missiles in Israel’s arsenal, the fighters could also pose a serious threat to tankers and other vital support aircraft without needing to engage Israeli fighters. The fact that all Israeli fighters other than the F-15 rely heavily on tankers to be able to engage Iranian targets provides significant opportunities to implement such tactics. Iran’s delays in procuring modern fighter aircraft since the UN arms embargo on the country was lifted in 2020 has been a major contributor to its adversaries’ relative freedom of action, and one which could be suddenly reversed should Russia move to expedite the deliveries of the Su-35s the country has ordered.&nbsp;