The Observer view on the Middle East crisis: Iran and Israel risk sparking all-out conflict

There have been many moments that have been described as milestones in the war that began when Hamas militants surged through the $1bn (£772m) fence constructed by Israel around Gaza on 7 October to kill more than 1,200 people, mostly civilians, and abduct another 251. With hindsight, we can now see that few of them were genuine inflection points.
The death toll resulting from Israel’s offensive in Gaza last week reached 40,000, according to Palestinian officials. The number does not differentiate between combatants and civilians but around two-thirds of those fully identified are women and children. Then there are those still under the rubble, who may total 10,000.
Israel says its forces have killed 14,000 Hamas operatives and accuses Hamas of using the civilian population of Gaza as a human shield. On Friday, the Israeli military issued evacuation orders to tens of thousands of people living in the “safe humanitarian zone” it had designated, saying rockets had been fired from the area. The identification of a polio case in Gaza underlines the depth of an entirely man-made humanitarian disaster.
Despite our weariness when told we have reached yet another critical moment in the conflict, this weekend is surely a perilous moment, as British foreign secretary David Lammy and Stéphane Séjourné, his French counterpart, write in the Observer today.
“Hostages taken by Hamas terrorists remain in chains… Fighting between Israel and Lebanese Hezbollah has intensified. Iranian threats of further escalation mean the risks of a full-scale regional war are rising,” they say, describing a “destructive cycle of violence”. Both ministers call for a ceasefire in Gaza, and call on Iran and Israel to avoid further escalation. Such calls have often been made, and equally often been ignored. One reason for this is that the use of violence gives policymakers the sense of controlling events. In reality, this is an illusion.
The bloody Hamas attack last year had multiple aims, some of which are still unclear. Yahya Sinwar, the Hamas leader who was the architect of the operation, believed that it would prompt other militant groups, such as Hezbollah, to launch offensives and that Israel would be paralysed by the number of hostages being held. He was wrong, and though Sinwar has influenced the course of events since, he has not controlled them.
Israel’s assassination of Ismail Haniyeh in Tehran last month is another example. Killing the political leader of Hamas was part of an explicit Israeli effort to assassinate the group’s top echelons but served other purposes: to boost domestic morale, rally support for an unpopular prime minister and regain the initiative in the war. But Israel now has limited control over what happens next. The decision over whether and how to retaliate is for Iran. Some in Tehran are tempted to meet violence with greater violence. Conservatives argue that Israel has to suffer consequences or will be emboldened.
In April, Iran responded to an Israeli strike in Damascus that killed two of its generals with a carefully calibrated launch of hundreds of missiles and drones targeted at largely unpopulated areas or military bases. This time, retaliation that causes more damage would probably lead to an all-out conflict. Iranian decision-makers would have limited influence on subsequent events, with potentially appalling consequences for their own country and the region.
Pointing this out to Iranian and Israeli leaders may have greater impact than yet more calls for peace and restraint. Such advice would be practical not performative. We encourage Lammy and Séjourné, as well as their counterparts elsewhere, to make this argument too as forcefully as they can.