A new umbrella: will Russia supply Iran with air defence systems?

Among the senior Iranian officials he met were Rear Admiral Ali Akbar Ahmadian, a senior Islamic Revolutionary Guard Corps commander and secretary of the Supreme National Security Council, and Mohammad Bagheri, a commander who is leading the planning for the strike on Israel.

"Russia is among the countries that have stood by the Iranian nation during difficult times," Pezeshkian told Shoigu, who is now secretary of Russia's security council.

Preparing for escalation

The alliance between Iran and Russia has deepened considerably since the Russian invasion of Ukraine in 2022, with Iran providing Moscow with drones and ballistic missiles to support its military offensive against Kyiv.

The upsurge in tensions between Iran and Israel in the wake of Haniyeh's assassination has prompted concerns among Western leaders that Iran is planning to launch revenge attacks, possibly involving Hezbollah.

US intelligence reportedly told US Secretary of State Antony Blinken that they expect two waves of attacks on Israel: one from Iran, the other from Hezbollah. Some Western governments are now urging their citizens to leave the region.

A statement issued by the Islamic Republic said it had a "legal right" to "punish" Israel for the assassination of Haniyeh and a senior Hezbollah commander in Beirut, while insisting that it was not looking to escalate regional tensions.

Moscow's concerns about a major escalation in hostilities were reflected in Shoigu's message to Iranian Supreme Leader Ayatollah Ali Khamenei. While condemning the killing of Haniyeh, Shoigu called on Tehran to show restraint and to avoid targeting Israeli civilians.

Friends on both sides

Having supported Russia in its war in Ukraine, Iran is now looking for Moscow to reciprocate in kind. Apart from asking Moscow to bolster Iran's air defences, the Iranians also asked Shoigu for Russian-made Sukhoi 35 fighter jets.

Yet just how far Moscow goes in providing such sophisticated weaponry to Iran will be interesting, since it could risk undermining Putin's strong personal relationship with Israeli Prime Minister Benjamin Netanyahu.

As Russian president, Putin has pursued a largely pro-Israel policy, becoming the first Russian leader to visit since 2005. He subsequently endorsed the building of a $60m Jewish Museum, to which he donated a month's salary.

A key factor in Putin's pro-Israel stance is the fact that there are an estimated 1.2 million Russian and former Soviet emigrés living in Israel, while many of the Russian oligarchs who support Putin also hold Israeli citizenship.

Today, Israel is home to the world's largest population of Jews from the former Soviet Union, with almost one in six Israelis now Russian speakers.

Deciding on priorities

Netanyahu is well aware of the political importance of Israel's large Russian Jewish diaspora. Largely right-wing, secular, and nationalist, this huge chunk of the Israeli population has been supportive of his Likud party for decades.

It is one reason why Israel has tried to stay neutral over the Russia-Ukraine conflict, Netanyahu having refrained from condemning Putin over the invasion, and refusing Western calls to join the sanctions regime against Moscow.

Another important factor in Israel's neutrality over Ukraine is the important relations Israel's military have with Russia's military in Syria, where Russia controls the skies but allows Israeli aerial sorties targeting Iranian proxies.

Publicly, Putin will want to repay Iran for its support in Ukraine. Privately, he will be very careful what he supplies. Putin will want to maintain Russia's good relations to Israel just as much as Netanyahu.

Some things are just not worth falling out over.