Israel did not have a realistic plan for regime change when it attacked Iran, multiple Israeli security sources have said, with expectations that airstrikes could drive a popular uprising driven by “wishful thinking” rather than hard intelligence.

Iran has now survived nearly two weeks of bombing raids and the assassination of Ayatollah Ali Khamenei, and Trump is publicly contemplating ending an increasingly costly war.

If Iran’s new leadership keeps its grip on power, the long-term measure of the success of the conflict may hang on the fate of 440kg of enriched uranium, buried under a mountain by US strikes last June, former and serving Israeli defence and intelligence sources said. Enough for more than 10 nuclear warheads, Iran could use it to race towards construction of a weapon if it stays in the country.

“These 440kg of uranium are one of the clearest litmus tests for how this war ends, whether it is a success,” said one former senior Israeli defence and intelligence official who worked on Iran. “We need to be in a position where either this material is out of Iran, or you have a regime where you are confident that it is safeguarded [inside Iran] in a very meaningful way.”

Hardliners in Iran have long argued a nuclear deterrent is the only guarantee of survival for the Islamic republic. The overwhelming military dominance of US and Israeli forces in this war is likely to bolster that view if the regime survives.

The US is reportedly weighing sending troops on an extremely high-risk mission to secure the uranium. Negotiations before the war also included proposals for Iran to surrender the enriched uranium to another country.

“It’s a high-risk game this war, because if it succeeds, it would completely change the Middle East for the best,” the former official said. “But if we bomb everything and the regime stays in power, and they continue to maintain those 400kg of uranium, I think we will be starting the countdown to an attempt by Iran to go to a nuclear weapon.”

Joab Rosenberg, the former deputy head of Israel’s military intelligence research division, was even more blunt, describing any conclusion of the war that leaves the uranium in Iranian hands as a pyrrhic victory.

“The worst result of this war will be the declaration of victory of the type of June 2025, leaving the Iranian regime weak with 450kg of enriched uranium in its hands,” he said in a social media post. “So they will 100% be going for a nuclear bomb and our victory will become our loss.”

The assassination of Ali Khamenei may have compounded the nuclear threat from Iran. He poured economic and political resources into a programme that could easily be turned to military use, but for decades held off on the final stage of ordering construction of a weapon.

The views of his son and successor, Mojtaba Khamenei, are less clear. “With [Ali] Khamanei we knew almost everything about his decision making,” said another former senior intelligence official. “He was doing a lot of things we were concerned about, and that’s why there was a war. But he never took the decision to run [to a bomb] no matter what.

“With Mojtaba, I am not so sure we have the knowledge to assess what he will do with the nuclear programme,” the source added. “He could run to a bomb right now.”

The devastation caused by Israeli and US bombing would delay work on a nuclear weapon, but even with limited technical capacity the political decision to move forward with creating a bomb would escalate the long-term threat to Israel, he added.

Despite these risks, the US-Israeli war has broad support inside Israel’s military establishment, multiple serving and former defence and intelligence officials have told the Guardian, reflecting popular backing in Israeli society.

After the 7 October 2023 Hamas-led attacks, Israel’s military has prioritised acting to remove potential immediate threats to Israel, such as Iran’s ballistic missile programme, as soon as possible, according to multiple sources.

Nearly two weeks of airstrikes have destroyed or degraded much of Iran’s military capacity, taking out missiles, launchers and the military industrial supply chains that produced them, as well as political leaders, military commanders, academics and engineers.

Regime change ‘wishful thinking’

The Israeli prime minister, Benjamin Netanyahu, and Donald Trump launched the war with calls for regime change, immediately turning the conflict into an existential one for Iran’s rulers. Trump may have been intoxicated by the success of his raid to capture the Venezuelan president Nicolás Maduro and replace him with more US-friendly elements from the same system.

For this report the Guardian spoke to a number of serving and former Israeli defence and intelligence experts, including individuals who had played key roles in the country’s long fight against Iran’s nuclear programme.

Some of them say it was never realistic to expect an air war could immediately collapse the Iranian government or replicate the policy pivot forced on Caracas.

“It’s wishful thinking,” said one of the intelligence sources. “We used to have a plan how to take out the ballistic missiles, how to deal with the nuclear sites, how to take care of the military industry in Iran. But I never heard that we knew how to do a campaign [of regime change] from the air.

“We never knew how to get into the heads of 90 million people. So how would we know how to assess whether they would go to the streets or not? We are hoping they will go.”

In January mass anti-regime protests were brutally repressed by the regime, with tens of thousands reportedly killed. At the time Trump promised “help is on its way”, and since the war began Netanyahu has repeatedly called on the Iranian people to rise up.

Israel says it is targeting the structures of domestic control to make this easier. Airstrikes have reportedly hit the Basij, the volunteer police arm of the Revolutionary Guards, and buildings belonging to internal security forces.

Another popular uprising during war was always extremely unlikely, said Sima Shine, an Iran specialist and former head of research at Israel’s Mossad intelligence agency. There have been no signs of Iranians taking to the streets or significant defections from security forces that could undermine their grip on the country since the US-Israeli campaign began.

“I belong to those who don’t think that regime change can happen from bombing from the outside,” Shine said. However, she does not rule out the longer-term security and economic impacts of the bombing campaign leading to the government’s collapse. “It’s not black and white. It might be that Iran will finish the war so weak, everything will be so fragile, that it will ease the capability for changes from outside the regime.”

Many in the Israeli intelligence and defence community who did not expect regime change also feared that a battered, decapitated Iran would pose significant nuclear risks if it retained possession of the enriched uranium.

Even so they backed a bombing campaign over further negotiations, on the grounds that airstrikes could take out many of Iran’s missiles and much of the industry that produced them, as well as further devastating its economy.

That prioritising of immediate tactical military dominance reflects the impact of 7 October 2023 on approaches to national security, multiple Israeli defence and intelligence officials have said.

Dramatic victories, but unable to capitalise

Israel’s priority now is to make Iran and its proxies as weak as possible as soon as possible, even though the war risks spurring longer-term Iranian efforts to develop a nuclear weapon, multiple current and former officials have said.

“After October 7, Israel is not the same state it used to be before. The policy changed completely. There is zero tolerance, about 70 or 80% of Israelis are not willing to accept any bullshit from our adversaries that want to kill us,” one said when asked about longer-term strategic fallout from the war. “The first priority of the IDF [Israel Defense Forces] is to protect our families … then we will deal with all the rest.”

Nearly two weeks of bombing has already destroyed much of Iran’s military industrial base, running through targets from missiles to the factories far downstream, and the academics and engineers who design and run the programme.

“The IDF are on the verge of concluding this campaign. They are not going to say this, because it’s a political directive [when it will end], but from a military point of view they’ve fulfilled almost all the mission,” he said. “Two weeks, and it’s over after that.”

The damage would take years to fully repair, a third former senior security official said, making Israel safer in the immediate future even without regime change. “This is not some small terror cell, it is a huge country with lot of academic, intellectual depth and resources. So once the kinetic phase of this war ends, assuming the regime is not toppled, we should expect a new weaponisation race.

“You need to target the experts, the facilities, the equipment, and in some cases at least, in the nuclear issue, the materials. If you achieve a severe blow on those capabilities, that can really delay renewal of the threat for a much longer period.”

The bombing has been more extensive than during the 12-day war in June, multiple sources have said. Netanyahu then claimed a “historic victory” had removed the threat from Iran’s ballistic missiles, but the country rapidly restored production.

Achieving freedom to operate in the skies of a vast and distant country, more than 1,000km away from Israel and with more territory than Germany, France and Spain combined, is another strategic success that will make it easier for Israel to project power at a greater distance in future wars.

Air defences cannot be taken out in a single surprise strike; gaining air superiority required waves of attacks against anti-air missile batteries, mostly launched when the enemy was prepared. Iran’s response to this onslaught has been to wage asymmetric attacks across the region and into Europe, pushing up fuel costs and destabilising regional economies.

Many Israelis who see this war as an existential struggle back a longer bombing campaign in the hope that if the regime is not destroyed, it could be weakened enough to cede control of the enriched uranium, handing Israel a “much broader deterrence”.

They are willing to risk extending an open-ended conflict that began in Gaza and has lasted more than two years on shifting fronts, moving on to Lebanon, Syria to Iran and Yemen.

As oil prices spiral, fuelling inflation and discontent, many leaders in the region and beyond are making very different calculations. Israel’s embrace of military power as the only path to security risks leaving it isolated in the Middle East and in the longer term perhaps internationally.

“Israel is not willing or able to capitalise on its dramatic military achievements by trying to move to the more political aspect of building new alliances,” another former senior official said. “I am fearful we will still be stuck in this place.”