“We believe that the United States of America and the president of the United States have an obligation to make sure that the region is going to a positive way and that the world is free from Iran that possesses (a) nuclear weapon,” former Israeli Defence Minister Yoav Gallant told CNN’s Bianna Golodryga in an interview.

Israeli Prime Minister Benjamin Netanyahu, meanwhile, used an ABC News interview this week to pour cold water on a diplomatic channel with Iran that Trump seems desperate to revive, saying it had been used to “string the US along”.

“I have to be back early for obvious reasons,” Trump said. “They understand. This is big stuff.”

He flies home to Washington as it reverberates with blunt warnings from some of the most influential opinion-shapers in MAGA media.

Personalities such as Steve Bannon and Tucker Carlson say that a decision to strike Iran would represent a repudiation of his 10-year-old political movement and “America First” principles.

“I don’t want the US enmeshed in another Middle East war that doesn’t serve our interests,” Carlson said on Bannon’s War Room show on Monday.

Synergy between right and left populist movements in America is also on display. Vermont independent Senator Bernie Sanders, who ran as a Democrat primary candidate in the 2016 and 2020 elections, said the US “must not get dragged into another of Netanyahu’s wars”.

Loud voices opposed to deeper US involvement underscore the painful legacy of the Iraq and Afghan wars, which created political forces that nurtured Trump’s populist uprising.

But the neoconservative interventionist wing of the GOP has not disappeared. Hawks such as Senator Lindsey Graham are trying to convince Trump that Israel’s blitz against Iranian air defences and a confluence of forces that have weakened the regime offer the US a chance to definitively end the nuclear aspirations of its 45-year foe and to transform the Middle East.

European leaders who met Trump in Canada brought to bear their own pressure, seeking to see whether the US would rein in Netanyahu amid concern over Trump’s suggestion that Russian President Vladimir Putin might join a peace effort.

Even Iran joined the cacophony, accusing Israel of sabotaging US nuclear talks with the Islamic Republic, a centrepiece of the president’s so far frustrated strategy of branding himself as a global peacemaker.

A decision that will define Trump’s presidency … and much more

Multiple voices bearing down on Trump reflect the gravity of a decision that will carry consequences that go beyond the always-heavy burden of whether to send American personnel to war.

Whatever he decides, Trump will set off consequences that will be pivotal for Israel’s security, the wider Middle East, and US power and influence. He can’t know whether a US attack on subterranean chambers in Fordow could succeed or whether it will suck the US deeper into a prolonged conflict.

Historically, Trump has balked at perceptions that his options are being narrowed — or that others are trying to make up his mind for him. So pressure from any direction risks being counterproductive.

Ironically, Trump set up this dilemma himself. His decision to walk away from a previous US nuclear deal with Iran in his first term delighted Israel — but laid the groundwork for a future crisis.

The raging debate in the MAGA movement that is splitting conservative media is a sign that Trump’s own support base is on the line, and that a legacy he promised would not be marked by foreign interventionism is also at stake.

Trump often creates shock and disorientates opponents by igniting confrontations that he later defuses or postpones. This is his preferred approach to trade wars. But there would be no going back from a US military strike with bunker-busting bombs at Fordow. Whatever the aftermath, the president would own it.

On Monday evening, the president wrote on Truth Social that “IRAN CAN NOT HAVE A NUCLEAR WEAPON” and said everyone should “immediately evacuate Tehran,” although he did not explain why he would issue such a warning.

Perhaps Trump is just playing for time or trying to scare Tehran back to the table. But maybe he really doesn’t know what he’s going to do.

A task only the US can accomplish

Iran has so far not directly targeted US bases or personnel, nor has it widened the conflict — for instance, by going after shipping in the Strait of Hormuz, which could trigger global economic shockwaves. That may be a sign that it wants to avoid pulling Trump in. But it is generally agreed that while Israel can delay Iran’s nuclear program, only the US can destroy it.

In an extraordinary interview with CNN’s Golodryga, Gallant warned that Trump had the future of the world in his hands.

“This could be a disaster for the world,” he said, referring to the possibility of an Iranian bomb. “And I believe that the determination of the American president that has been shown recently will pave the way to America to enter into this very important operation,” Gallant said. “The president of the United States (has) the option to change the Middle East and influence the world.”

Another former Israeli defense minister, Benny Gantz, also noted unique US military assets. “I do remember that the United States is much stronger than us. It has capabilities that we don’t possess. But I’m not in a position to recommend to the president of the United States what to do,” Gantz told CNN’s Anderson Cooper. “I am sure that the United States, if it decides to act, will do it for its own interests and not our interests only.”

Israel’s President Isaac Herzog implied that Trump had been taken for a ride in his pursuit of a diplomatic solution. “You can speak (of a) peaceful diplomatic (solution), and on the other hand, underneath you move forward to the bomb. And that was exactly the situation,” Herzog told Wolf Blitzer on The Situation Room.

And Netanyahu aimed a message at Trump’s MAGA critics. “Today, it’s Tel Aviv. Tomorrow, it’s New York. Look, I understand ‘America First.’ I don’t understand ‘America Dead’. That’s what these people want,” Netanyahu told ABC.

‘We have to think this through’

A sincere debate over Iran is under way inside Trump’s grassroots movement, and it is causing splits across the right-wing media empires that normally support the president unequivocally.

Bannon argued that a major new US escapade in the Middle East would deviate from the core principles of Trumpism, which involved avoiding “forever wars,” expelling undocumented migrants, securing the border and confronting China to bring back US manufacturing jobs.

He said on War Room that Israel had to make sovereign decisions for itself, as any nation should. “But when you start making decision that are predicated on the assumption that America is going to come in, not just for defence but for offence … No, we have to make decisions that put America first.”

Bannon went on: “This has to be thought through. This Pearl Harbour-type attack on the mullahs is fine for Israel. But is it right for the United States?” He concluded that the real war that the US faces is against undocumented migrants on its own soil.

A fundamental question underpins this internal MAGA debate: If “America First” is not about avoiding the kind of Middle East quagmires that ruined President George W Bush’s Republican presidency, does it really mean anything?

Trump’s political success was forged in the US heartland, in the kind of towns that sent their young to fight and die in the post-9/11 wars. Those conflicts started with shock-and-awe initial success like the one Israel is celebrating with its elimination of top Iranian military leaders and nuclear scientists.

But they degenerated into bloody slogs that still haunt American politics. No one is openly talking of a betrayal yet. But just a month ago, in Saudi Arabia, Trump restated his opposition to interventionism and nation-building in the Middle East.

On the left, there was already antipathy toward Netanyahu because of the terrible toll on Palestinian civilians of his war on Hamas. But Sanders also seemed to be vying for Trump’s attention, warning in a statement, “The attack was specifically designed to sabotage American diplomatic efforts: Israel assassinated the man overseeing Iran’s nuclear negotiating team, despite the fact that further talks with the United States were scheduled for Sunday.”

An allergy to such foreign entanglements is not just endemic to Trump’s political project: his two predecessors, Barack Obama and Joe Biden, felt much the same way.

But now it’s fallen to Trump to make a decision that every modern president dreaded.