Contrasting reactions to the chance killing by Israeli soldiers of Hamas’s top leader, Yahya Sinwar, offer a chastening guide to the dismal, dead-end politics of the Middle East. Sinwar, reputed mastermind of the 7 October 2023 massacre of about 1,200 Israelis, has paid a fitting price for his crimes. It would have been preferable had he faced trial. The same holds true of Ismail Haniyeh, Hamas’s political chief, assassinated by Israel in Tehran in July. Yet both these men lived by the sword. They knew the score.

The killing is being widely described as a watershed moment that could presage an end to the multi-fronted war that erupted after 7 October. It is likened in importance to the US assassination of Osama bin Laden, who plotted the 9/11 attacks – and was similarly celebrated in Israel and western capitals last week. Yet such sweeping assessments may be premature.

The unyielding reactions of the main players give no grounds for optimism that Sinwar’s death has changed the fundamentals of the conflict or brought it any closer to resolution. This is disappointing but unsurprising. Much innocent blood continues to be shed on all sides, primarily in besieged Gaza refugee camps such as Jabalia. Why imagine yet another killing will bring peace?

The US alone is out of tune with this negative chorus. After opposing a ceasefire for months, president Joe Biden now wants to use Sinwar’s death to increase pressure to stop the Gaza fighting and forge a hostage deal. A ceasefire, he believes, is the key to de-escalation in Lebanon and would reduce the risk of an Israel-Iran war. “Let’s make this moment an opportunity to seek a path to peace [and] a better future in Gaza without Hamas,” he said.

Yet, as so often in the past year, no one directly involved seems to be paying much attention to Biden. US weakness and indecision, dramatised by Washington’s failure to condemn brutal Israeli army tactics in Gaza and ensure the unobstructed delivery of humanitarian aid, has been further underscored by numerous, futile diplomatic interventions. Israel’s hard-right coalition, led by prime minister Benjamin Netanyahu, does not want peace. It wants total victory, at all costs.

Defying significant domestic as well as American pressure, Netanyahu insists the war will go on. He knows outrage at the Palestinian death toll – now about 42,500 – is hurting Biden and Kamala Harris, ahead of next month’s US election. But he doesn’t care. He calculates that Biden will not halt arms supplies. And he hopes likeminded Donald Trump, a foe to Palestinian rights and justice, will beat Harris on 5 November.

Reaction to Sinwar’s killing from Hamas and its allies in what Iran calls the “axis of resistance” has been similarly uncompromising. Sinwar’s deputy, Khalil al-Hayya, insisted nothing had changed. Sinwar’s “banner will not fall”, he said, and he would be replaced. Hamas demands Israel halt the war, end its occupation of Gaza and free Palestinian prisoners before it will accept a ceasefire and release the estimated 100 Israeli hostages still unaccounted for.

This show of defiance contains an element of bravado. Hamas has been badly damaged. Its new leaders must be more flexible in any resumed peace talks. They should free the hostages immediately. Yet the group’s statements again confound those in Israel and the west who think an ideology and a cause can be destroyed with bullets and bombs. Ideas, even bad ones, don’t die that easily.

Intransigence was on display in Lebanon, too, where Israel is pursuing an expanded military intervention to halt rocket attacks from Hamas’s ally, Hezbollah. Israel’s assassination of Hezbollah’s leader, Hassan Nasrallah, has not deterred its fighters any more than Sinwar’s death has apparently deterred Hamas. Hezbollah is now threatening further escalation. At the same time, Iran is urging anti-Israel militias in Iraq, Syria and Yemen to maintain the “spirit of resistance” and fight on.

Israel’s military response to Iran’s firing of 181 ballistic missiles at the country earlier this month, while delayed, is certainly coming. This imminent prospect of renewed, head-to-head confrontation is another reason to question whether Sinwar’s killing really marks a turning point – or is another grim milestone on the road to hell.

Israeli analysts suggest Netanyahu, who has long sought a showdown with Iran to halt its nuclear programme and stymie region-wide subversion, now sees an opportunity. His tail is up, as are his poll ratings. He believes he is winning, and by doing so, can absolve his guilt for 7 October security failures. Biden is weak, the US distracted by its election. The usual restraints are loosening. Will Netanyahu choose this juncture to go in for the kill? On the evidence of the past 12 months, there is little this dangerous man will not do.

All the signs point not to a peaceful post-Sinwar resolution but the continuation and possible intensification of this conflict across the Middle East. Meanwhile, the avoidable suffering of the trapped, starving and terrorised people of Gaza goes unchecked.

Only the US, for all its failings, can put a stop to this – necessarily with the strong, unified support of Britain and other democracies. It must do so now by finally standing up to Netanyahu and his far-right cronies and issuing an immediate demand to cease and desist in Gaza, backed by weapons cutoffs and punitive sanctions.

If he does nothing else before he quits, Biden must bring Israel’s rogue prime minister to heel.

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