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Iran has warned Israel it will pay a price for attacking its embassy compound in Damascus on April 1, an air strike that killed two Iranian generals, among seven officers of Islamic Revolutionary Guard Corps (IRGC) and nine others, including some Syrians.
This leaves the question of which weapons Iran has at hand to strike Israeli targets.
In the past, Iran has delivered long-range drones and missiles to allies to attack Israel, accepting losses among those allies in retaliatory air strikes.
Mark Pyruz, an expert on Iran's security services, says observers should not expect the Iranians to accept what he calls “reflexive control” after the attack, whereby Iran restrains its retaliatory instincts for fear of provoking something worse.
This was the case after the US assassination of Maj Gen Qassem Suleimani in Iraq in 2020, when Iran halted direct attempts at retaliation after firing one heavy barrage of missiles at American forces.
Today, Iran could be willing to take more losses and more risk, if history is a guide.
“The Iranian-Israeli contest stretches back to the First Lebanon War [1982], with attrition and replacements a feature of raised levels of conflict,” Mr Pyruz says. "A response isn't expected to divert global public focus away from Israel's disadvantageous Gaza policy but rather a continuation of targeting observed during this present crisis."
This form of proxy warfare is already playing out on the Israel-Lebanon border in daily clashes between Iran-backed Hezbollah and Israel.
Hezbollah is thought to possess a number of guided ballistic missiles that have not yet been used, which could strike Israeli airports and power plants – but the group has hinted it will not play a central role in an Iranian strike.
It is suspected that Hezbollah has not yet used Khaibar-1 missiles, with a 100km range, or Fateh 110 missiles, with a 160km range, because such a move could rapidly expand the war.
This leaves two other proxy fronts in Iraq, where analysts say Iran has sent allied militias shorter-range ballistic missiles, including the Al Aqsa missile thought to have capability of travelling less than 100km.
The militias have, however, fired drones towards Eilat, thought to be Shahed 110s, commonly used by Iran-backed groups against US forces.
If that continues, Israel could retaliate inside Iraq – Israeli jets may have bombed the militias in a series of mysterious air strikes and explosions in 2019.
On the Syrian front, where these groups operate frequently alongside Hezbollah, Israel has launched hundreds of air strikes, accepting responsibility for some over a period of more than 10 years, but commenting seldom on individual attacks.
This is one reason why attacks from Syria have been relatively rare.
Unless supplied with longer-range missiles, there is little more Iran-backed groups in Iraq can do except hope that one of their drones hits a high-value target, such as the Eilat naval base.
This leaves two possibilities: an increased supply of weapons to Houthi militias currently blockading the Red Sea, sending more advanced missiles such as the Toufan ballistic missile and Quds-3 cruise missile, both of which can hit Israel and have come close on two occasions.
This option is not ideal, due to Israel’s now reinforced air defence network.
“The Houthis have been firing at Eilat and southern Israel since October, with very little to show for their efforts and expenditure,” says Aron Lund, of the Century International think tank. "These attacks seem to have no strategic material impact on the conflict whatsoever.
“One might justifiably ask why they’re willing to throw away all these expensive and hard-to-come-by weapons without hitting anything that matters or seriously complicating Israeli operations.”
This limited capability leaves some form of direct Iranian attack on Israeli interests – such as a terrorist attack on embassies, hinted at in IRGC-linked media – or against Israel itself.
Iran has used Shahed 136 drones to attack vessels owned by Israeli companies, before the current Gaza war, hitting the Pacific Zircon, owned by Israeli billionaire Idan Ofer, in 2022, and striking the Mercer Street, also linked to an Israeli company, killing two sailors, in 2021.
Direct confrontation?
Tehran’s most extreme option is attacking Israel directly.
Israel is well within range of missiles such as the Khormashahr 4, with a 2,000km range, or even the shorter-range Shahab. The accuracy of these weapons at such long distances is unknown, unlike the 500km-range Fateh 313, which is accurate to tens of metres.
Without accuracy, Iran might be satisfied with hitting a city or sparsely populated area, depending on whether it is prepared for a limited war or major Israeli retaliation, if many Israelis are killed.
Iran’s Shahed-149 “Gaza” drone, with a claimed range of 2,500km, might contribute to such an attack but it presents a relatively big target for air defences.
"Israel has intercepted drones from Syria in the past and intercepted Hezbollah drones. Most of the Iranian proxies use similar models for drones. They don't have the capabilities to avoid modern air defences, but that doesn't mean they can't find complex routes that keep them away from air defences for part of their flight path," says Seth Frantzman, author of Drone Wars: Pioneers, Killing Machines, Artificial Intelligence, and the Battle for the Future.
Israel, meanwhile, has long-planned to use its F-35I stealth fighter to strike Iran in the event of war, or to hit Iranian nuclear facilities. Such an attack could be augmented by non-stealth aircraft such as the heavily armed and fast F-15.
But these operations might be limited, given Israel’s lack of in-flight refuelling for massive air operations at long range, and US-purchased KC-46A Pegasus refuelling tankers are not expected to be delivered until 2025.
In any case, even a limited clash between Iran and Israel would represent another tipping point towards a worsening regional war.
