After weeks of threats and a massive US military build-up, the missiles began to rain down on Tehran on Saturday morning, the first day of Iran’s working week, triggering panic across the capital.
With waves of air strikes, the US and Israel ignited their second war against the Islamic republic in eight months, warning it would be on a far larger scale than Israel’s 12-day war in June. This time the US is at the forefront, with President Donald Trump describing the attack as “massive”, warning that “bombs will be dropping everywhere” and seemingly pushing for the ultimate objective: regime change.
“I say tonight that the hour of your freedom is at hand. Stay sheltered,” Trump said in a video. “When we are finished, take over your government.”
Like the last war in June — which was started by Israel and briefly joined by the US — it has come while the Trump administration was engaging in talks with Iran to secure a deal over its nuclear programme. Those talks always seemed doomed to fail, with war becoming ever more inevitable despite the efforts of Arab and Muslim states who fear it will trigger a regional conflict that will spill over their borders.
Trump, spurred on by Israeli Prime Minister Benjamin Netanyahu, was in a rush and seeking to force Iran’s capitulation as he ordered the biggest military deployment in the Middle East since the US-led invasion of Iraq in 2003.
Iran’s supreme leader Ayatollah Ali Khamenei, deeply distrustful of Trump, was never likely to bend the knee — in his mind surrendering to the ideological enemy would present a graver threat to the regime’s survival than a conflict.
The regime’s calculus is not that it can match the far superior firepower of the US or Israel, but that it can endure and land enough blows to raise the cost to its foes so they ultimately de-escalate. It was always a high-risk gambit by Khamenei, the 86-year-old cleric whose near four-decade rule has been characterised by defiance in the face of challenges, be they external or internal.
But Trump, who came to office promising to end America’s wars, is taking the biggest gamble of his presidency. The bloody history of US interventions in the Middle East shows that those who launch military assaults are rarely able to control their outcomes.
The republic is at its weakest and most vulnerable since the 1980s war with Iraq. Its proxies, historically considered integral to a national security strategy built on the concept of asymmetrical warfare, have been severely debilitated through two years of regional conflict. Iran’s own defences were largely destroyed by Israeli air strikes — first in October 2024, and again last June.
Its remaining legitimacy at home was shattered by the deadly crackdown on anti-regime protests last month. The republic has been deeply infiltrated by Israeli intelligence and appears in a spiral of decay.
Many experts overestimated Tehran’s capacity to challenge Israel’s military after Hamas’s October 7, 2023 attack triggered regional conflict, and it has never faced such a massive, sophisticated military threat as Trump’s assault poses today.
To Trump and Netanyahu this appears the moment to land a decisive blow. Yet while the regime was severely battered during last June’s war, it was far from defeated. It emerged intact, with no signs of defections. It took solace from the fact that at least some of its missiles were able to penetrate Israel’s defence systems and in effect shut down the country for two weeks.
Both sides will have learnt lessons from that conflict and the Iranian regime has had months to begin to replenish its missile arsenal.
Iranian officials have repeatedly warned that they will target US bases in the region, which are far closer to the republic than Israel, meaning Tehran could use short-range missiles that would arrive in minutes.
Tehran has also previously threatened to block the Strait of Hormuz, the vital maritime trade route through which about a third of the world’s seaborne crude oil passes.
Iran has not acted on that threat, but the regime has never before been backed into the perilous corner it finds itself in now, facing a battle for its survival. The past two years’ attacks on merchant shipping in the Red Sea by Iran-backed Houthi rebels demonstrated the disruption that missile and drone barrages can cause.
Arab states — fearful of the chaos a war could unleash — have also warned the US about the potential threat to energy facilities. In 2019, Iran was blamed for a missile and drone attack in Saudi Arabia that temporarily knocked out half the crude output of the world’s top oil exporter. Iran also shares the North Field, the world’s largest natural gasfield, with Qatar. Any damage to that could significantly hit gas markets.
Trump seems to think that Iranians will exploit the assault to rise up and finish the job for him.
During Israel’s June war, the regime was buoyed by the fact that Iranians put aside their loathing of their leaders to rally around the flag in the face of foreign aggression. The US apparently is calculating that there will be no repeat of that same sense of nationalism this time, after the brutal crackdown against protesters last month, which killed thousands.
The anger of the population is palpable. But worn down by oppression and violence, people may also be fearful for their own lives, both from bombs, the chaos and the threat of the regime’s reprisals.
Iranian analysts caution that even if Khamenei is assassinated, it would not necessarily trigger the regime’s collapse, pointing to an institutionalised bureaucracy and ideological power centres that are likely to keep up the fight, most notably the 180,000-strong Revolutionary Guards.
Trump has overseen several swift, contained military operations in his second term: the bombing of Iran’s nuclear facilities last June, which he claimed “obliterated” the programme, and the kidnapping of Venezuelan President Nicolás Maduro in January.
But Iran should not be compared to Venezuela, and previous US interventions in the Middle East, from Iraq to Libya, have left a bloody, chaotic legacy. Iran is a vast, multi-ethnic country of over 90mn people, and if the regime did disintegrate, there is no telling what would come next.
There is no organised internal opposition, and while Reza Pahlavi, the son of the last shah, has grown in prominence in exile, he is a divisive figure. Few believe he has the support, capacity or structures to successfully step into the fray.
“This is a regime change campaign through and through, but just like during the 2003 Iraq war the US has not engaged in day-after planning,” said Sanam Vakil, Middle East director at Chatham House. “There are enormous risks.”
She warned that without a plan or structure in place, regime collapse “could produce lawlessness and chaos”.
“This might be a good outcome for Israel that might finally see the defeat of its longtime adversary, but this will be devastating for the Iranian people who will suffer through a long arduous transition,” Vakil said.