A Defensive Alliance:

On 9 December, White House National Security Council Coordinator for Strategic Communications John Kirby warned that Russia had offered Iran "an unprecedented level of military and technical support," which had turned the relationship into a "full-fledged defense partnership." Kirby claimed that Iran planned to establish a joint production line for drones in Russia, while other reports circulated that Russia intended to export Su-35 jets to Iran and train Iranian pilots to operate them. These dire warnings reflected US alarm about Russia’s use of Iranian Shahed 136 and Mohajer-6 UAVs in Ukraine and its potential acquisition of Iranian ballistic missiles.

Although Russia has cooperated extensively with Iran in Syria since 2015 and supported letting the UN arms embargo on Iran expire in October 2020, the war in Ukraine has brought bilateral military cooperation to a new level. This expansion is the result of both Russia and Iran’s edge in various military spheres and their desire to undermine the US-led economic order. Nevertheless, Ukraine’s growing ability to neutralize the threat posed by Iranian UAVs, Russia’s desire to maintain cordial relations with Iran’s regional adversaries, and Iran’s concerns about secondary sanctions could eventually limit the scope of this cooperation.

Driving Forces

Russia and Iran’s expanded defense cooperation enables both countries to fill gaps in their respective military arsenals. Russia theoretically has the capacity to domestically produce equivalents of the Turkish Bayraktar TB2 or Mohajer MALE drones but lacks the ability to manufacture long-range kamikaze drones like the Shahed-136 due to Western sanctions. Iranian drones previously contained small German and Dutch precision-engineered engines that are no longer available to Russian manufacturers. The rapid depletion of Russia’s missile stocks, which is apparent from its use of 1980s-era AS Kent cruise missiles stripped of their nuclear warheads, will push Moscow to consider replenishing its stock with Iranian missile technology.

By importing Su-35 jets from Russia, Iran is taking a step towards revitalizing its antiquated and depleted air force. The Islamic Republic of Iran Air Force relies heavily on Cold War-era aircraft, such as the US F-14, Russian Su-25 and MiG-29, and Chinese Chengdu J-7. It has not yet recovered the combat capacity that it lost during the 1980-88 Iran-Iraq War. If Russia redirects the 24 Su-35s that were originally marketed for Egypt to Iran and helps Iran domestically produce Su-35s, Iran will begin to reduce its air power deficit relative to Saudi Arabia and the UAE. Additionally, if Russia sells Iran two S-400 air defense systems, as has been speculated in recent weeks, the Islamic Revolutionary Guard Corps and its proxy militias will be able to more effectively counter increased Israeli airstrikes in Syria.

The expansion of arms sales between Russia and Iran also underscores their shared commitment to resisting Western sanctions. On 30 March, Russian Foreign Minister Sergei Lavrov pledged to work with Iran on countering "unilateral illegitimate sanctions," which Moscow routinely refers to as "hybrid warfare" and Tehran often labels economic terrorism. Although Russian hopes of using Iran as a backdoor route for oil exports have been dashed by the impasse in Joint Comprehensive Plan of Action (JCPOA) negotiations, arms sales would improve cooperation between Russian and Iranian financial institutions in combatting money laundering. Russia is also seeking to learn from Iran’s decades of experience in weathering Western sanctions. Russian Telegram channels have praised Iran’s "rational modernization" of its military, while Moscow sees Tehran’s focus on precision-guided missiles and UAVs as an effective model for its own military modernization in an era of sanctions.

Various Limits

Despite the marked growth of Russian-Iranian military cooperation in recent months, it is important not to overstate the long-term potential of this partnership. Russia’s use of Iranian UAVs helped it attack Ukrainian electricity infrastructure, but has not enabled Russia to secure aerial superiority over Ukrainian skies. Moreover, Ukraine’s NATO-class air defense systems have become increasingly effective in limiting the damage inflicted by Iranian UAVs. On 14 December, Ukraine claimed to have shot down all 13 UAVs that Russia fired on Kyiv. The imminent arrival of Patriot systems will further bolster Ukrainian military preparedness against Iranian drones. Russia’s Rybar Telegram channel recently noted that Ukraine was using a Shahed-136 equivalent in Zaporizhzhia. This suggests that Iranian UAVs are not necessarily giving Russia a decisive edge in the drone war. 

Moreover, economic and geopolitical considerations are likely to restrain the scope of future Russia-Iran military cooperation. Western countries do not believe Iran’s claims that the latter supplied only a "small number" of UAVs to Russia prior to the Ukraine war or Russia’s assertions that it only uses domestically-produced drones in Ukraine. Instead, the US, UK, and EU have sanctioned Iran for supplying UAVs to Russia. Although Iran recently shipped a fresh batch of UAVs to Russia, these sanctions could alter its calculations regarding ballistic missile transfers to Moscow. Iran reportedly ruled out selling Russia 700-kilometer-radius Zolfaghar missiles and planned to modify exports of the 300-kilometer-radius Fateh-110 missile system in accordance with UN Security Council resolutions.

Despite Russian frustrations with Israel’s cautiously pro-Ukrainian stance, Russia and Israel continue to coordinate on deconfliction in Syria. Israel has also resisted pressures to impose sanctions on Russia. Israeli Defense Minister Benny Gantz’s plan to help Ukraine develop a missile warning system underscored the potential backlash of Russia’s purchase of Iranian equipment. Moscow will take due note of the recent warning from Prince Faisal bin Farhan, the Saudi Foreign Minister, regarding the threat of Iranian UAVs, as Russia seeks to expand commercial ties with Saudi Arabia and secure Riyadh’s long-term support against Western oil price caps. Russia’s unwillingness to sell S-400s to Iran after publicly expressing openness to these exports is likely driven by a continuing desire to appease its partners in the Arab world.

While Russian-Iran relations are poised to improve in 2023, the scope of cooperation on UAV and ballistic missiles might be reaching its limits. The long-term impacts of Russian strikes on civilian infrastructure in Ukraine, the speed of NATO air defense deliveries to Ukraine, and the severity of sanctions against Iran will all play a crucial role in determining the future extent of the Moscow-Tehran security partnership.