Israel's attack on Iran last month and the US bombing of the country's nuclear facilities, the first-ever direct US attacks on Iranian soil, were meant to cripple Tehran's strategic capabilities and reset the regional balance.

The strikes came after 18 months during which Israel had effectively dismantled Hamas in Gaza, dealt a devastating blow to Hezbollah in Lebanon, weakened the Houthis in Yemen, and seen the collapse of the Assad regime in Syria - a longstanding and key Iranian ally.

From a military standpoint, these were remarkable achievements. But they failed to deliver the strategic outcome Israeli and US leaders had long hoped for: the collapse of Iran's influence and the weakening of its regime.

Instead, the confrontation exposed a deeper miscalculation. Iran's power isn't built on impulse or vulnerable proxies alone. It is decentralised, ideologically entrenched and designed to endure. While battered, the Islamic Republic did not fall. And now, it may be more determined - and more dangerous - than before.

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Israel's attack - dubbed "operation rising lion" - began with attacks on Iranian radar systems, followed by precision airstrikes on Iranian enrichment facilities and senior military officers and scientists. Israel spent roughly US$1.45 (Pound 1.06 billion) billion in the first two days and in the first week of strikes on Iran, costs hit US$5 billion, with daily spending at US$725 million: US$593 million on offensive operations and US$132 million on defence and mobilization.

Iran's response was swift. More than 1,000 drones and 550 ballistic missiles, including precision-guided and hypersonic variants. Israeli defences were breached. Civilian infrastructure was hit, ports closed, and the economy stalled

The day after the US strikes, the Israeli prime minister, Benjamin Netanyahu, spoke with Donald Trump about a ceasefire. He and his generals were reportedly keen to bring the conflict to a speedy end. Reports suggest that Netanyahu wanted to avoid a lengthy war of attrition that Israel could not sustain, and was already looking for an exit strategy.

Crucially, the Iranian regime remained intact. Rather than inciting revolt, the war rallied nationalist sentiment. Opposition movements remain fractured and lack a common platform or domestic legitimacy. Hopes of a popular uprising that might topple the regime expressed by both Trump and Netanyahu were misplaced.

In the aftermath, Iranian authorities launched a sweeping crackdown on suspected dissenters and what it referred to as "spies". Former activists, reformists and loosely affiliated protest organisers were arrested or interrogated. What was meant to fracture the regime instead reinforced its grip on power.

Most notably, Iran's parliament voted to suspend cooperation with the International Atomic Energy Agency (IAEA), ending inspections and giving Tehran the freedom to expand its nuclear programme - both civilian and potentially military - without oversight.

Perhaps the clearest misreading came from Israel and the US treating Syria as a template. The 2024 fall of Bashar al-Assad was hailed as a turning point. His successor, Ahmed al-Sharaa - a little-known opposition figure, former al-Qaeda insurgent and IS affiliate - was rebranded as a pragmatic reformer, who Trump praised as "attractive" and "tough".

For western and Israeli strategists, Syria offered a both a way to weaken Iran and a blueprint of how eventual regime change could play out: collapse the regime, install cooperative leadership in a swift reordering process. But this analogy was dangerously flawed. Iran's stronger institutions, military depth, resistance-driven identity and existence made it a fundamentally different and more resilient state.

While Iran's regional network has taken significant hits over the past year -Hamas dismantled, Hezbollah degraded, the Houthis depleted, and the Assad regime toppled - Tehran recalibrated. It deepened military cooperation with Russia and China, secured covert arms shipments, and accelerated its nuclear ambitions.

Both Israel and Iran, however, came away with new intelligence. Israel learned that its missile defences and economic resilience were not built for prolonged, multi-front warfare. Iran, meanwhile, gained valuable insight into how far its arsenal - drones, missiles and regional proxies - could reach, and where its limits lie.

Most of Iran's drones and missiles were intercepted - up to 99% in the cases of drones - exposing critical weaknesses in accuracy, penetration, and survivability against modern air defenses. Yet the few that did break through caused significant damage in Tel Aviv, striking residential areas and critical infrastructure.

This war was not only a clash of weapons but a real-time stress test of each side's strategic depth. Iran may now adjust its doctrine accordingly - prioritising survivability, mobility and precision in anticipation of future conflicts.

Internally, Israel entered the war politically fractured and socially strained. Netanyahu's far-right coalition was already under fire for attempting to weaken judicial independence. The war has temporarily united the country, but the economic and human toll have reignited deeper concerns.

Israel's geographic and demographic constraints have become clear. Its high-tech economy, tightly integrated with global markets, could not weather prolonged instability. And critically, the damage inflicted by the US bombing was more limited than hoped for. While Washington joined in the initial strikes, it resisted deeper involvement, partly to avoid broader regional escalation and largely because of the lack of domestic appetite for war and high potential for energy inflation, if Iran was to close the Strait of Hormuz.

The war of 2025 did not produce peace. It produced recalibration. Israel emerges militarily capable but politically shaken and economically strained. Iran, though damaged, stands more unified, with fewer international constraints on its nuclear ambitions. Its crackdown on dissent, withdrawal from IAEA oversight, and deepening ties to rival powers suggest a regime preparing not for collapse, but for survival, perhaps even confrontation.

The broader lesson is sobering. Regime change cannot be engineered through precision strikes. Tactical brilliance does not guarantee strategic victory. And the assumption that Iran could unravel like Syria was not strategy, it was hubris.

Both sides now better understand each other's strengths and limits, a clarity that could deter future war - or make the next one more dangerous. In a region shaped by trauma and shifting power, mistaking resistance for weakness or pause for peace remains the gravest miscalculation.