Benjamin Netanyahu, the biggest loser in last week’s preliminary deal to halt the US-Israel-Iran war, will be remembered – and reviled – as the man who put the Middle East to the sword. Whether the “problem” was Hamas in Gaza, illegal West Bank land seizures, supposed Israeli-Arab fifth columnists, peace campaigners’ aid flotillas, Hezbollah in Lebanon, hostile militias in Syria, Iraq and Yemen, or Tehran’s hardline Islamic regime, the Israeli leader’s “solution” was always the same: extreme, often lawless violence that invariably made matters worse.

The unprovoked, illegal war against Iran was the ultimate expression of the Netanyahu doctrine – the disproportionate application of brute force. Predictably, it too, has failed. Donald Trump is desperately arguing that the ceasefire memorandum he signed in Versailles (of all places!) is not the lame capitulation it so self-evidently is. But while the US president may survive this humiliation – despite global scepticism and mockery – the likely consequences of the debacle for Netanyahu, his brother-in-harms, are career-ending serious. In many respects, Israel’s longest-serving prime minister is already yesterday’s man.

His political obituary reads like a criminal indictment. For decades, Netanyahu resisted a two-state solution with the Palestinians. He failed to prevent the terrible Hamas atrocities of 7 October 2023, then visited genocidal vengeance on Gaza. He clung to power by giving far-right politicians key government roles, to his country’s lasting chagrin and shame. He undermined the internationally endorsed 2015 nuclear pact with Iran, whose subsequent repudiation by a credulous Trump led directly to this year’s disastrous, self-defeating conflict.

Yet the main reason Netanyahu is now hurtling towards political oblivion, even as autumn elections approach, is none of the above. It’s because he has poisoned and perhaps fatally weakened the vital US-Israel “special relationship”. He and Trump are barely on speaking terms. Fairly or not, the White House, and an American public already shocked and alienated by Israel’s war on Gaza, blame him for drawing the US into an unwinnable fight on the basis of glib predictions of easy victory and regime collapse. And now that peace is at hand, they fear Netanyahu is sabotaging it by continuing the war in Lebanon.

In the decades after Israel’s independence in 1948, the two countries often clashed – over Suez in 1956, over Israel’s Arab wars, peace plans, borders and settlements. But when the cold war ended, and the Soviet threat evaporated, their strategic and security interests, underpinned by shared democratic values, increasingly converged. US military aid to Israel mushroomed, as did the Washington lobbying power of its supporters. The US became Israel’s chief defender and indispensable ally – Israel America’s leading regional partner.

The consensus began to fall apart in 2015 when Netanyahu and pro-Israel organisations in the US mounted a huge campaign to derail Barack Obama’s attempt at a rapprochement with Iran. “The Israel-advocacy complex’s blitz failed to stop the nuclear deal. Instead, it demolished its own vestigial facade of bipartisanship. Pro-Israel groups soon began to function openly as a wing of the Republican party,” wrote Haaretz columnist Joshua Leifer. Trump’s first term deepened the political polarisation. He ghosted the Palestine Liberation Organization, moved the US embassy to Jerusalem and recognised Israeli sovereignty over the Golan Heights. “Trump has arguably done more to push rank-and-file Democrats away from Israel than any pro-Palestinian activist,” Leifer noted.

Netanyahu’s subsequent actions – his calculated embrace of hard-right nationalist-populist politics, support for unchecked territorial expansion and settler land-grabs, and his failed wars in Gaza, Lebanon and now Iran – have further fractured the old consensus. Recent polls indicate a startling turnaround. For the first time, more Americans sympathise with Palestinians than with Israelis. Many question whether the alliance serves US interests and want to halt or limit military aid. Ironically, present-day criticism, like past applause, is bipartisan, coming from both leftwing progressives and Maga supporters.

If reports of Trump’s profanity-laden personal attacks on “crazy” Netanyahu are to believed, then they reflect a broader collapse in mutual trust – and the resulting shock waves may have permanent geopolitical consequences. Having achieved something none of his predecessors achieved – roping the US into an all-out war – Netanyahu is now at the centre of another unprecedented development: a profound US-Israel strategic schism.

Trump’s Iran deal has left many Israelis aghast, and not only those on the right. The war enjoyed strong public support on the basis of Netanyahu’s promises to finally eliminate the Iranian nuclear and ballistic missile threat, degrade Tehran’s regional proxies, principally Hezbollah, and spark regime change. None of these objectives has been achieved. Worse, from Israel’s perspective, Iran’s revamped, Revolutionary Guards-dominated regime is emerging defiant and emboldened: witness its plan to charge transit fees in the strait of Hormuz.

Speaking after the G7 summit last week, Trump eviscerated Netanyahu’s red lines. He said Iran must be allowed to enrich uranium, had a right to ballistic missiles, and should be given back billions of dollars in frozen assets as part of a broader lifting of sanctions. The US also backed Iran’s demand for an immediate, permanent ceasefire in Lebanon – a position angrily underscored by vice-president JD Vance, who ordered Netanyahu to stop fighting and toe the line. The US is “the only powerful ally” Israel has left, Vance warned ominously. By any conventional measure, this open confrontation is catastrophic for Israel.

Netanyahu is cornered. If he tries to demonstrate sovereign freedom of action by defying Trump, he could provoke Iran into restarting the war and wreck the peace deal. After Tehran pulled out of follow-up talks on Friday in Switzerland because of Israeli strikes on Hezbollah, US officials claimed the two sides had agreed to reinstate an earlier ceasefire. Yet if Netanyahu tamely submits to Trump’s diktats, especially over a full Lebanon troop withdrawal, any remaining credibility he has with voters and his far-right allies may be lost. Either way, the “special relationship” is unlikely to recover quickly.

The possible ramifications of this rupture are giddying. It may come to mark the high-point of Israeli exceptionalism, the collapse of Netanyahu’s dream of a greater Israel as the dominant Middle East power – and the end of unquestioning US support and unconditional military aid. It could scupper hopes of extending Trump’s Abraham Accords to Saudi Arabia and other Gulf states that are busy recalibrating postwar loyalties. Trump’s unjust Gaza “peace plan” may deservedly hit the dust. It could be the moment Iran’s isolation finally eases, when Tehran comes in from the cold. Crucially, Israel will be less, not more, secure.

Netanyahu staked everything on a comprehensive, legacy-boosting victory over his Iranian nemesis – and he lost, badly. Now he must reap the whirlwind. Don’t make more trouble or more excuses, Bibi. Don’t wait to be pushed or sacked. Resign.

• Simon Tisdall is a Guardian foreign affairs commentator