Israel fended off hundreds of drones and missiles fired by Iran on Saturday using an enviable combination of its own sophisticated air defences and the critical support of western powers and Arab partners.
But Israel may not be able to pull off that performance and sustain crucial outside support forever — especially if the Jewish state launches a major retaliatory strike against Tehran, which would escalate regional tensions in a way that none of Israel’s allies want.
While only a handful of Iran’s missiles, and none of its cheap diesel-powered drones, made it through Israel’s multi-layered Aerial Defense Array last weekend, Tehran and its proxies are sitting on a bank of missiles and drones estimated to number in the tens of thousands.
In an all-out war, even Israeli military officials admit at least some of these would break through, especially in the face of repeated salvos fired from multiple directions by Iran-armed militants in Lebanon, Yemen, Syria and Iraq.
Such an assault would resemble the desperate situation faced by another western ally: Ukraine.
“We in Ukraine know very well the horror of similar attacks,” President Volodymyr Zelenskyy said in a video post on Sunday, in which he condemned Iran’s attack on Israel, but also urged western leaders to provide Kyiv with the same military assistance they had just deployed to help Israel.
Ukraine’s air defences late last year were intercepting almost all of Russia’s aerial assaults, which use weaponry similar to that deployed by Iran at the weekend. But those defences have since been depleted by a constant stream of enemy missiles, and last week Ukraine succeeded in stopping less than two-thirds of a massive salvo that destroyed Kyiv’s biggest power plant.
“Words do not stop drones and intercept missiles,” Zelenskyy fumed in the video. “Only tangible assistance does.”
That need for continued “tangible assistance” is a central consideration for Israel’s war cabinet as it weighs how to respond to Iran’s attack. Tehran has said that if Israel retaliates, its subsequent “response will be considerably more severe”.
But the US, UK and France have said they would not support Israel in a retaliatory strike against Iran, counselling restraint given the apparent minimal damage from Tehran’s assault.
“Alliances work both ways,” said Ben Wallace, the former UK defence secretary. He recalled how Israel refused to help Ukraine when Russia first launched its all-out war against Kyiv and rejected Zelenskyy’s request for an Iron Dome air defence system .
“Israel needs to understand that Iran and Russia are joined at the hip, and there is another Jewish president that needs help,” Wallace added, in reference to Zelenskyy.
Iran’s attack against Israel last weekend was massive, by any standard. Tehran launched about 170 drones, more than 30 cruise missiles, and about 120 ballistic missiles, according to data from the Institute for the Study of War, in waves timed so that the 300-plus weapons arrived in Israel within 10 minutes of each other.
Unlike Russia’s recent attacks on Ukraine, however, nearly all the incoming Iranian missiles and drones were intercepted. That was partly achieved by Israel’s well-stocked and multi-layered air defences, built and paid for largely with US military assistance.
But it was also thanks to substantial help from a US-led coalition, and the fact that the Iranian salvo was telegraphed in advance, allowing ample time to prepare.
US and UK jet fighters, combined with Jordanian air defences, downed multiple drones and missiles long before they reached Israel’s borders. Centcom, the US military’s central command for the region — which has included Israel since 2021 — co-ordinated intelligence and radar alerts from around the region, and took down nearly a third of the incoming missiles and drones.
Israel threw significant resources at repelling the Iranian barrage, instead of carefully marshalling its air defences as Ukraine is having to do after two years of Russian assaults.
“Israel defended itself under ideal conditions last weekend when it faced a one-time punitive strike,” said Franz-Stefan Gady, an associate fellow at the International Institute for Strategic Studies think-tank in London.
“The real danger for Israel is that its air defences become saturated during a sustained war . . . that is, if it faces a large number of aerial attacks, over very short intervals, which eventually overwhelm every kind of air defence system,” he added. “Even Israel would then sooner or later deplete its stocks [and] it would face similar challenges as Ukraine does now.”
The aim of Tehran’s barrage, its first direct attack on Israel since the Islamic revolution in 1979, was to overwhelm Israel’s air defences through sheer volume.
This is exactly what Russia has sought to do to Ukraine with its biggest attacks, such as the nearly 500 drones and missiles that Kyiv has said Moscow launched in similarly staggered waves over five days at the start of this year.
Wallace, who was UK defence secretary for four years until he stepped down last August, said many of the aerial attack capabilities that Tehran claimed to have were a “fantasy” and suffered from a big “say-do gap”.
Even so, the missile arsenals of Iran and its proxies, especially Lebanese group Hizbollah, are substantial in terms of volume, and Wallace said they “could definitely get some things through” in a sustained fight.
Even on Saturday, several Iranian ballistic missiles penetrated Israel’s air defences. The Israeli military on Monday also denied US reports that half of Iran’s missiles had failed to launch or crashed before reaching their targets.
“The drone and missile threat from Tehran ought not to be downplayed,” said Behnam Ben Taleblu, senior fellow at the Foundation for Defense of Democracies think-tank, who pointed out Iran has the region’s largest arsenal of ballistic missiles, estimated to number in the low thousands.
“Volleys of rockets interspersed with precision-guided missiles from Hizbollah could still saturate Israeli defences, especially if part of a surprise attack . . . [and if] another direct launch came from Tehran,” he added.
Last weekend was not the first time Israel has fought off swarms of rockets. In an 11-day war in 2021, Hamas fired off nearly 5,000 rockets from Gaza, with each salvo made up of 50 or more projectiles.
Israel does not disclose the size of its missile reserves. Yet even though Hamas’s rockets are rudimentary compared with the more sophisticated missiles in Iran’s and Hizbollah’s arsenals, Israel still used up so many $50,000 Tamir interceptors during the attack that the US made an emergency $1bn allocation to replenish them.
That US commitment continues for now. Even at the peak of his frustration with Israeli Prime Minister Benjamin Netanyahu’s conduct of the war in Gaza, US President Joe Biden has pledged to maintain Washington’s “ironclad” commitment to Israel’s security.
But there are complicating factors. For one, there is a global shortage of interceptor missiles effective against ballistic missile attacks, such as those used in the US-made Patriot and Israel-manufactured Arrow air defence systems.
Some of the more sophisticated versions can take up to two years to manufacture. They are also expensive: one former Israeli military official estimated the cost of Saturday night’s defence at more than $1bn in expended material, not including what it cost the US, France and UK to send jets.
At the same time, Israel’s western allies are overstretched and have to balance their own military and budget priorities.
In the US, Congress has stalled on approving military aid packages to Ukraine and Taiwan, as well as a $14bn White House request for additional funds for Israel’s military that includes more than 14,000 interceptors, said people familiar with the request.
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As for Europe, it is struggling to meet Ukraine’s military and air defence needs. Kyiv’s requests this year for seven more Patriot batteries have been rebuffed by several European countries , although they have 100 of the batteries in their arsenals, according to Josep Borrell, the EU’s top diplomat.
“Our public line is all about Israel’s right to defend itself,” said one senior European official. “But internally, there is a growing tension about support for Israel versus Ukraine.
“The Middle East is going to be volatile forever. But if Ukraine loses to Russia, that would be a step change for Europe and Nato. Where do our strategic priorities really lie?”
Additional reporting by Christopher Miller in Kyiv