Russia has deployed its most advanced S-400 air defense system to Syria, but the sophisticated weapon does not seem to work against Israeli jets.

It is an open secret that Moscow, an ally of Syrian President Bashar al-Assad, allows Israel to conduct air strikes against both the Syrian army and Iranian militias operating in the country. Russia’s supremacy over Syria’s airspace helped turn the conflict in Assad’s favor, so why does it allow Israel to carry out its operations unimpeded?

On December 28, Israeli warplanes attacked the container complex at the port of Latakia, in a part of Syria where Russia maintains its main naval base. The strikes hit a yard thought to house Iranian weapons shipments.

This was Israel’s second attempt to destroy the cargo. The first one took place on December 7, but was apparently less successful than the latest air strike, which caused significant damage.

That night, neither Russia’s S-400 nor Syria’s air defense systems attempted to hit the Israeli planes. The truth is, Russia never activates its air defense systems against Israeli jets. Such passivity is believed to be part of a wider deal between the two countries.

After the Kremlin started its military adventure in Syria in 2015, it reached an agreement with the Jewish state: Israel reportedly pledged to guarantee the safety of Russian citizens and military installations in Syria during its strikes on Iranian militias and Syrian military targets. In return, Moscow promised not to use its weapons to repel Israeli attacks.

In that case, why did the Syrian army not react with its own weapons on December 28?

According to Kremlin officials, a Russian military transport aircraft was descending to land at the Khmeimim Air Base – some 25 kilometers from Latakia – as the Israeli strikes took place, hence Syrian air defenses were not activated to repel the attack.

There is no doubt that the Kremlin wants to avoid incidents like the one in 2018 when a Russian reconnaissance plane, returning to Khmeimim with 15 servicemen on board, was mistakenly hit by a Syrian S-200 surface-to-air missile. Moscow blamed Israel for the incident, claiming that Israeli jets put the Russian Il-20 plane into the path of Syrian air defense systems after failing to give Russian command enough warning of a strike on Syrian targets.

There was speculation that the Il-20 was hit by an Israeli F-16 jet, but even if that was the case, the Kremlin never went beyond its usual verbal condemnation of the incident.

The tragic event did not have an impact on relations between Russia and Israel. Although Russian’s military operating in Syria has the power to prevent Israel from hitting Iranian and Syrian targets, Russia constantly turns a blind eye to Israel’s activity in Syria. The attack on Latakia port was no exception.

For Assad and the Iranians, the Kremlin acts as an unreliable ally and partner. In 2010 Moscow refused to sell S-300 air defense systems to Tehran, bending to pressure from the United States and Israel. In 2019, Russia again rejected an Iranian request to buy S-400 systems, concerned that the sale would stoke more tension in the Middle East.

Even now that the UN Security Council embargo on conventional arms shipments to Iran is no longer in effect, it remains highly uncertain if Moscow will sell the S-400 to Tehran. The Kremlin is allegedly concerned that Israel could respond by providing sophisticated drones to Ukraine, where there are fears of an impending war with Russia.

Therefore, not to jeopardize its ties with Israel, Russia will probably refrain from a deeper military cooperation with Iran.

As former Israeli national security adviser Meir Ben-Shabbat recently said, Russia shares Israel’s view that Iran is a “destabilizing force in the Middle East.” He also stressed that Moscow’s position on Iran is closer to Israel’s than what is revealed in public.

Russia’s passive position regarding Israeli air strikes in Syria clearly demonstrates that the Kremlin is not willing to harm its relations with Israel for the sake of its alliance with Syria and a potential strategic partnership with Iran.

Just a few days before the Latakia strike, Russian President Vladimir Putin and his Israeli counterpart Isaac Herzog held a phone call and discussed bilateral cooperation.

Relations between Israel and Russia are historically entwined around World War II, the foundation of Israel and the migration of Russian Jews to live there.

There are up to 1.5 million Russian-speaking Israelis in the Jewish state, and some Russian oligarchs, such as Mikhail Fridman and German Khan, have taken up Israeli citizenship.

Given that oligarchs play a very important role in Russian politics, and Moscow aims to preserve good relations with all actors in the Middle East, the Kremlin is expected to keep preventing Damascus from responding to Israeli air strikes.

Syria is the weakest link in Russo-Israeli relations, and Tehran, for its part, is not in a position to pressure Moscow to enable Iranian proxies to use Syrian territory as a base against Israel.

Russia will continue to balance between the so-called Axis of Resistance (Syria, Iran and Tehran’s proxy militias) and their arch-enemy Israel. But historic and current ties mean the balance is more likely to tip in favor of Israel.