The coordinated strikes on Iran launched by the United States and Israel in the early hours of Saturday morning formally reignited a conflict that had been simmering since last summer’s 12-day war. They targeted key command structures and killed senior figures, most notably Iran’s supreme leader Ali Khamenei, who had been in power since 1989. Donald Trump marked his demise with a post saying “one of the most evil people in history” was dead, adding: “This is not only justice for the people of Iran, but for all Great Americans.”

Israel has also published reports claiming that Mohammad Pakpour, commander of the Islamic Revolutionary Guard Corps (IRGC), defence minister Aziz Nasirzadeh and Admiral Ali Shamkhani, head of the defence council, have also been killed. In response, Iranian forces have fired missiles and drones at Israel, at US bases in the Gulf, Iraq and Jordan, and at some civilian targets across the Gulf. Events are moving quickly, but far from predictably.

An ebullient Trump embarked on this attack casting it not as a limited action, but as a decisive campaign to eliminate what he called a longstanding threat to the US, one that he argued previous US presidents had been unwilling to confront directly.

It followed rounds of regionally supported diplomacy aimed at a preliminary nuclear deal. But instead of allowing those efforts to mature Trump, perhaps swayed by Israeli prime minister Benjamin Netanyahu and conservative hawks in his administration, chose to strike now, at what is widely seen as a moment of Iranian weakness. He immediately suggested that the Iranian people should now determine their own future, making it clear that Washington supports internal regime change and reiterating that as he announced Khamenei’s death on Saturday night. “This is the single greatest chance for the Iranian people to take back their country,” he posted on Truth Social.

Some context is useful in terms of timing, because this weekend’s escalation was not a sudden rupture but the culmination of two years of widening confrontation. Since 7 October 2023, Israel has conducted sustained military campaigns not only against Hamas in Gaza, Hezbollah along Israel’s northern border and Houthi targets tied to Red Sea attacks, but indirectly against Tehran itself. These operations steadily eroded Iran’s forward defence strategy and weakened its core military capabilities. What remained comparatively intact until now was Iran’s territory, its missile programme and, crucially, the regime leadership.

The strikes have yielded immediate results. Yet wars rarely unfold according to initial design. While Iran can by no means match US conventional capabilities, it retains asymmetric tools. Its only viable option has been to widen the theatre, distributing the costs of conflict and increasing regional risk. The immediate retaliation against Israeli territory and US installations across the Gulf signals precisely that strategy. This has been a dangerous gamble, particularly for Tehran’s fragile ties with neighbouring states in the Gulf, but it sees sustained escalation as the only means to secure an eventual ceasefire.

It is important to note that the three principal actors enter this confrontation with distinct objectives. For the Islamic Republic, the priority is survival: achieved by absorbing the shock, maintaining sufficient military and political cohesion, and continuing its military response. Iran is not fighting to win in conventional terms, but the regime is fighting to endure.

Trump, in contrast, appears to be seeking a decisive outcome that shows he has neutralised a longtime US adversary. On Saturday night he promised that the bombing “will continue, uninterrupted throughout the week or, as long as necessary to achieve our objective” and his strategy rests on the assumption that overwhelming force targeting infrastructure, strategic assets and senior leadership can dismantle Iran’s strategic posture and compel either capitulation or internal rupture.

Israel’s objectives broadly align with Washington’s, though its focus is narrower. While Netanyahu continues to call on Iranians to rise up and respond to a historic opportunity to change the regime, Israel is really focused on ensuring that Iran remains internally preoccupied and strategically, if not permanently, weakened.

After the first few days of bombing and Khamenei’s death, several interconnected pathways now lie ahead. In the coming few days, the White House could halt operations having inflicted substantial damage – and test whether coercion produces concessions and de-escalation measures conducted under duress. What remains of Tehran’s leadership would then face a stark calculation whether preserving some semblance of the regime justifies submission to Washington’s demands.

With Khamenei removed from the scene, the system does not automatically collapse. The constitutional mechanism for succession would likely be activated, with the assembly of experts formally appointing a new supreme leader. In practice, however, the decisive influence would rest with the revolutionary guard and the security establishment, which would seek to manage the transition tightly and prevent fragmentation of the elite. A collective leadership arrangement, even if temporary, could emerge to stabilise the system – but here it would be vulnerable to military pressure, if not further US and Israeli pressure.

Alternatively, prolonged military pressure could expose fractures within Iran’s political elite. Economic strain, military losses and internal rivalries might weaken central authority and create openings for internal contestation that might be supported by opposition groups.

The most destabilising scenario would be uncontrolled fragmentation. Libya offers a cautionary parallel. The fall of Muammar Gaddafi did not produce an orderly transition, but institutional collapse, competition between militias and external intervention layered on to domestic rivalry. Iran is a far more complex state, with stronger institutions and a deeper bureaucratic tradition, but decapitation of the regime without a managed political transition could still empower armed factions and invite proxy competition on its territory.

What is already clear is that the region will not revert to its pre-war equilibrium. Gulf states that cautiously pursued de-escalation with Tehran now face renewed exposure. Energy markets and maritime security, particularly around critical chokepoints, will remain sensitive to further escalation. Regional actors will reassess alliances and defence postures considering the risks revealed by direct US and Israeli action.

Iran may endure this war, but the Islamic Republic as we have known it will not survive unchanged. The decisive phase of this conflict will not be the opening strikes, but the emergence of a political order from sustained military pressure. The US may achieve its immediate objectives. The more consequential question is whether it is prepared for the Iranian and regional landscape that follows.