A couple hours after midnight on June 22, a small mountain range about 200 kilometers southwest of the Iranian capital erupted in a series of earthshaking explosions.
The mountain range was Fordow, where Iran has spent years building a sprawling facility deep underground to enrich uranium for use in civilian power plants – or, as Israel insists, for use in a nuclear weapon.
The explosions were from a dozen of the largest conventional bombs in the US arsenal -- the 13,000-kilogram GBU-57 Massive Ordnance Penetrator – dropped by one of the most sophisticated airplanes in the US Air Force – the B-2 bomber.
As the dust settles over Fordow and two other sites hit by US munitions the coming days will reveal what this means exactly: Will all-out war erupt? Will Iran will retaliate against US bases in the region? Will Tehran choke off global oil supplies through the Strait of Hormuz? Will Israel keep up its unprecedented barrage of Iranian sites? Is the United States about to get involved in another full-scale Middle East war?
For the moment, however, this is what you need to know:
Before And After: The Iranian Nuclear Sites Targeted By US Airstrikes
What Happened?
Around 2:30 a.m. local time (12:30 a.m. CET), a squadron of seven B-2 bombers arrived high over the Fordow complex after traveling thousands of kilometers from their bases in the US Midwest. U.S. officials said the jets dropped 14 GBU-57 bombs, known also as “bunker busters” for their ability to burrow deep into the ground, then explode with a delayed fuse, theoretically destroying entrenched facilities, like Fordow.
SEE ALSO: Can A Strike On A Deeply Buried Enrichment Site Disable Iran's Nuclear Program?
At the same time, more than two dozen Tomahawk cruise missiles were fired by one US submarine in the Persian Gulf at another Iranian nuclear site: Isfahan. Two GBU-57 bombs were also dropped on the third site targeted in the US strikes, Natanz.
In all, 125 US aircraft were involved, including fighter jet escorts and tanker refueling plane, US officials said.
What Was Damaged?
Iranian authorities have broadly confirmed the sites were attacked. And US President Donald Trump claimed the Fordow, Natanz, and Isfahan facilities were “completely and totally obliterated.”
It’s very unclear, however, what exactly was damaged and to what extent.
Natanz and Isfahan had already been targeted by Israeli jets over the past 10 days of punishing air strikes.
Isfahan is where fuel rods had been built for nuclear power plants, according to the Nuclear Threat Initiative, a Washington think tank, although that effort slowed due to Western sanctions.
Natanz, meanwhile, has at least 50,000 centrifuges, housed in its underground structures, according to the think tank. Those, however, are not as deeply buried as Fordow.
Fordow was of particular interest to Israeli intelligence, as well as US agencies, due to its location deep in the mountainside. The facility, which was monitored by the International Atomic Energy Agency, or IAEA, housed thousands of precisely engineered centrifuges used in enriching uranium.
Up to a certain threshold, enriched uranium is used in fuel to power electricity generating plants. Above a certain level, it’s considered “weapons grade.”
More than 400 kilograms of the uranium hexafluoride gas – a key step of the enrichment process -- had already been enriched to 60 percent, the IAEA said in a report last month. That level is considered highly enriched, but not weapons grade. A confidential 2023 report, meanwhile, seen by CNN, said the IAEA discovered near weapons-grade uranium at Fordow.
Iran has repeatedly insisted its nuclear activities are strictly for civilian purposes.
What About War?
Israel hailed the attacks, saying they were a “crucial step in stopping the Iranian regime’s aggression and its ability to pose a threat to the region and the world.”
Iranian officials, meanwhile, reacted with condemnation, warning of “dangerous consequences and the far-reaching implication of [the US] act of aggression. Iran’s top diplomat, Abbas Araqchi, announced he was flying to Russia – a close though restrained ally of Iran – for talks with President Vladimir Putin.
At a news conference hours after the bombing, Araqchi did signal a possible hint of compromise, by saying “the door to diplomacy” should always be open. But, he added, "this is not the case right now."
In the run-up to the bombings, Washington had leaned heavily on Tehran amid high-stakes negotiations over the fate of its nuclear ambitions. And as the Trump administration’s public and private messaging hardened in the days preceding the bombings, European diplomats got more engaged to avert an attack.
Whether Iran is prepared to either go all-in for war, or retaliate directly against US military assets in the Middle East, is an open question.
The Islamic Revolutionary Guards Corps, Iran’s leading military branch, said the country reserved the right to respond in self-defense and warned the United States would “await regrettable consequences,” according to a statement on the state news agency IRNA.
In January 2020, after a U.S. drone fired a missile that killed a top Iranian general, Iran retaliated with barrage of ballistic missiles at U.S. facilities in Iraq, including the Al Asad Air Base. No deaths were reported, though about 100 U.S. personnel reportedly suffered traumatic brain injuries.
The United States bases in Qatar, Kuwait, Saudi Arabia, and the United Arab Emirates; Bahrain is home to the headquarters of the U.S. Navy's 5th Fleet.
Still, it is not clear if it even has the ability to retaliate.
Over the past 10 days of Israeli pummeling, many Iranian missile facilities, air bases, air-defense batteries, and weapons plants have been damaged or destroyed, limiting Tehran’s options.
Still, Iran has other tools.
For example, its cyber capabilities are well documented, and hackers linked to the Islamic Revolutionary Guards Corps have been accused of attacking Israeli systems in the past.
And Iran’s parliament on June 22 called for closing the Straits of Hormuz, the chokepoint waterway from the Persian Gulf to the Indian Ocean, where major oil tanker traffic passes en route to global markets.
Closing it down would be an earthshaking event for oil prices.
What About Politics?
The attack is a watershed moment for Trump, whose political rise was fueled in part by his – and many Americans’ – fatigue with aftereffects of the US invasions of Afghanistan and Iraq, and US military operations in Syria, often lumped together as America’s “forever wars.”
Many of Trump’s top advisers, including Vice President JD Vance, have sought to pull back on US interventions abroad. In the days before June 22, there were open clashes in US political circles debating whether the Trump administration should again involve the US military in another Middle East conflict.
After the attack, dubbed Midnight Hammer, Trump and other US administration officials offered constrained justifications, emphasizing that the goal was not “regime change” – toppling the Iranian government – nor was Washington planning to get deeply involved in the conflict between Israel and Iran, which is likely to continue.
“This is most certainly not open-ended,” Defense Secretary Pete Hegseth told reporters June 22.
In Congress, Democrats slammed the attack; most Republicans lawmakers endorsed it; a handful of Republicans, however, including Marjorie Taylor Green, the outspoken Republican House member, wrote on social media: “This is not our fight.”
“We’re not at war with Iran,” Vance told NBC News hours after the attack. “We’re at war with Iran’s nuclear program.”