How much closer are we to all-out war in the Middle East?

Chris Stevenson analyses how will Israel, Iran, Hamas and Hezbollah could respond to two high-profile killings

Demonstrators with a portrait of assassinated Hamas chief Ismail Haniyeh in Tehran (AFP via Getty Images)

The strikes came just hours apart.

The first on southern Beirut, with Israel claiming to have killed senior Hezbollah commander Fuad Shukr – who the US believe has been a senior adviser to the Lebanese milita's leader Hassan Nasrallah. Hezbollah has not confirmed Shukr's killing, but said he was in the building that was hit.

The second came in Tehran, taking out the head of Hamas' political leader Ismail Haniyeh. While Israel has not officially claimed the assassination, prime minister Benjamin Netanyahu has spoken about the desire to take out Hamas senior leadership in revenge for the 7 October terror attack inside Israel that triggered Israel's war in Gaza.

Thanks to that war in Gaza, the Middle East has become a tinderbox, where one miscalculation between Israel, Iran or any of the Tehran-backed groups Hamas, Hezbollah or the Houthis in Yemen could bring wider war to the region.

So where do these latest strikes take us?

Israel

The strike in Beirut was a response to a rocket attack on the Israeli-occupied Golan Heights on Saturday which killed 12 people, mostly children. Israel says Fuad Shukr was behind the attack, while Hezbollah has denied any involvement. A response was always coming – Israel and Hezbollah have been trading rocket fire on the Israeli-Lebanon border since the war in Gaza started – but Western allies of Israel had been urging Netanyahu to show restraint, while Hezbollah had warned that any strike on their stronghold in Beirut in particular would be met in kind.

In the wake of the strike the Israeli military said there would be no change in their defensive posture and that there would be no new instructions for Israelis on taking shelter, suggesting that they consider the matter closed and did not anticipate an immediate Hezbollah reaction.

Israel will expect some kind of response from Hezbollah, but will have hoped their signalling that they consider the matter finished would bring a proportionate – and manageable – rocket response from Hezbollah.

Damaged vehicles are seen after an Israeli strike on Beirut’s southern suburbs (Reuters)

But the assassination of Ismail Haniyeh complicates matters. The fact that it was on Iranian soil means that Hezbollah may now coordinate a response with Tehran or Hamas. Or it may make their own response, likely a rocket and missile barrage or barrages, even stronger.

The strike on Haniyeh also changes the situation around Gaza. Haniyeh, based in Doha, had been a key interlocutor between mediators Qatar and Egypt over talks for a ceasefire and hostage-release deal over Gaza, and his death has already been condemned by Qatar. Other countries across the region will also be unhappy. Turkey’s foreign ministry has already summed up the the mood – accusing Netanyahu of having "no intention of achieving peace".

On the flip side, the killing of Haniyeh may offer Netanyahu a chance to wind down the military offensive in Gaza, having finally got a target that was near the top of their most wanted list. But the Israeli prime minister has shown no intention of stopping up to this point, as much as Western allies – including staunch supporter the US – have been pushing for a ceasefire. Netanyahu will no doubt laud Haniyeh's death as making Israel safer. But the families of the hostages still in Gaza, many of them already angry at Netanyahu for not bringing them home will see any

Washington's mantra has been that Israel has the right to defend itself in the wake of the Hamas attack on 7 October that killed around 1,200 Israelis and saw another people 250 taken hostage. But it is getting increasingly difficult to stop escalations such as the two most recent strikes from sending the Middle East into all-out war. Expect some even more frantic diplomacy from nations around the region and beyond as Israel awaits the response to its actions.

Speaking about the threat of war with Hezbollah, Israeli defence minister Yoav Gallant said on Wednesday: "The performance [last] night in Beirut was focused, high quality and contained... We don't want war, but we are preparing for all possibilities, and that means you must be prepared as needed, and we will do our job at all the levels above you," he said.

Hezbollah

Hezbollah is a heavily armed militant and holds significant political sway in Lebanon.

Its military wing is one of the most powerful forces in the region, equipped with up to 200,000 missiles and rockets, as well as attack drones. It is separate to the Lebanese army, and is much stronger.

The trading of cross-border fire with Israel has stepped up in recent weeks, with the rocket hitting the Israel-occupied Golan Heights causing a spike in tensions that will only be made worse by the strike on Shukr and the killing of Haniyeh. The fact that there has been no significant response to the strike on its senior commander Shukr yet opens the door for coordinating any reaction with Iran.

Israel seeking to highlight that it wants no further escalation may have been aimed at keeping Hezbollah from hitting back hard, but was undermined by the killing of Haniyeh.

Palestinians attend a protest after the assassination of Hamas leader Ismail Haniyeh in the occupied West Bank (Reuters)

The rhetoric from Hezbollah will always be strong, but so far it has shown little appetite for an all-out war with Israel on the Lebanon border as was seen in 2006. But there is less and less room to manouvere every time there are such strikes and counterstrikes. A response will be needed to the hit on Shukr, but it is the size and breadth of the rocket and missile barrage that will likely come will be crucial as to what comes afterwards. If Hezbollah fires into Israel in a way that overwhelms Israeli air defences and potentially kills civilians, then war becomes significantly more likely.

Iran

The assassination of Haniyeh will be deeply embarrassing to Tehran. It comes a few months after two Iranian generals were killed in what was believed to be an Israeli strike on Iran's consulate in Syria. The deaths prompt Iran to launch an unprecedented attack against Israeli territory, launching 300 missiles and drones – but the drones took hours to reach Israel, allowing them and Western allies to intercept the vast majority.

Tehran will always talk tough and Iran's supreme leader Ayatollah Ali Khamenei has vowed revenge, claiming Israel had "prepared a harsh punishment for itself" after Ismail Haniyeh was killed in a pre-dawn air strike in the Iranian capital Tehran.

The Iranian leader said in a statement on his official website: "We consider his revenge as our duty," adding Mr Haniyeh had been "a dear guest in our home". Tehran will not want to spark a war over what is taken for granted by many leaders of Hamas – death by Israel – but being unable to protect an ally on its own territory leaves it needing to save face.

There may come a reaction directly from Tehran in terms of more drones or missiles. or Iran may coordinate responses from proxies across the region, including the Houthis in Yemen, militias in Iraq or even Hamas and Hezbollah themselves.

Hamas

Until the strike on Haniyeh, Hamas had avoided much of its top leadership being killed during the 10 months of war in Gaza, including Yahya Sinwar – who is believed to be the mastermind of 7 October – is still at large in Gaza.

Hamas has become used to replacing commanders killed by Israel over the years, but the loss of a high-profile figure like Haniyeh will leave a big hole in operations, as Haniyeh was in control of Hamas' relationships with Iran and other allies across the region/. Hamas will now be focused more on finding Haniyeh's successor in what could be a complicated and prolonged process, while it will certainly hit ceasefire talks with Israel hard. Iranian state television said that Haniyeh’s death would delay the negotiations by “several months”.

Given the military offensive by Israel in Gaza, Hamas' ability to respond directly to Haniyeh's killing has diminished, but we may see some rocket fire into Israel. Sinwar, who is Hamas' military leader in Gaza, is significantly more of a hardliner than Haniyeh who was seen as more pragmatic (relative to Sinwar). So it is unlikely that there will be any softening of the position of Hamas in relation to the war in Gaza – at least in the short term – in the wake of Haniyeh's killing.