Israel says its military action against Iran is intended to prevent the Islamic Republic from acquiring a nuclear weapon. As the United States considers joining Israel’s fight, the finer details of Iran’s nuclear weapons program and the negotiations to end it are fading into the background, and the WMD rationale used to justify action is being transformed into a catch-all assertion that Tehran is a “threat to the Western World.”

President Donald Trump’s language turned increasingly bellicose in the aftermath of Israel’s initial military strikes, calling for Iran’s “unconditional surrender,” while also threatening Iran’s leadership. He has approved a plan to strike at a key nuclear site, according to multiple defense officials — and says his decision about whether to execute the action will come “within two weeks,” according to a spokesperson.

“I’m not looking for a cease-fire, we’re looking at better than a cease-fire,” Trump told reporters as he flew back to the U.S. from the G7 summit in Canada.

For months, under two presidents, the United States had actively sought to prevent Israel from attacking Iran directly. When Israel began its strikes last week, Trump was in the middle of negotiations with Tehran, securing a nuclear deal with Iran having become the centerpiece of his foreign policy, after failing to make progress on a peace deal in the war between Russia and Ukraine.

Israel’s early strikes focused on nuclear facilities, long-range attack capabilities, and key military leaders and nuclear scientists. The campaign apparently had been organized months prior, involving not just air strikes, but also commando raids, assassinations, and even drones smuggled into and operated from inside Iran itself.

“Israel has been very methodical in terms of what they’ve been targeting,” says Dr. Nicole Grajewski, a fellow in the Nuclear Policy Program at the Carnegie Endowment for International Peace, with expertise in Iran. “There’s a logic behind it, and it’s actually been quite damaging for Iran.”

Creating a nuclear weapon requires access to uranium; the ability to mine and process the metal ore into a gaseous state; construction and operation of centrifuges to enrich the radioactive material to a high grade of purity; and the technical expertise to oversee that process and construct a nuclear device.

Military applications become distinguishable from civilian use during the enrichment phase. Civilian fissile material is enriched to a low grade — around five percent purity — while weaponized applications require highly enriched uranium, as pure as 90 percent or more.

Iran is a signatory to the Nuclear Non-Proliferation Treaty, or NPT, which strictly regulates and oversees the technical aspects of nuclear programs to ensure a country is not creating nuclear weapons.

Israel’s strikes began less than 24 hours after the International Atomic Energy Agency (IAEA) approved a resolution saying Iran was in non-compliance with the NPT, with “undeclared nuclear material and activities at multiple undeclared locations in Iran.”

“It is a fact that Iran was not providing the IAEA with the necessary clarity on many activities taking place there,” Rafael Grossi, the director-general of the IAEA, said in an interview. “Iran is the only country in the world accumulating highly enriched material at almost military levels, in an amount that would allow for the manufacturing of several nuclear weapons.”

Iran has multiple nuclear sites, but the most concerning for Israel has been the uranium enrichment facilities buried underground in Fordow, about 100 miles to the south of Tehran. The complex housing the facilities was excavated beneath a mountain of solid rock, as deep as 300 feet beneath the surface.

This is beyond the reach of most conventional munitions designed to destroy bunkers. But U.S. military planners — who conducted a simulated test of an attack on Fordow at a range in Nevada in 2019 — believe the site could be destroyed by a series of strikes using a specific deep-penetration munition: the GBU-57 Massive Ordnance Penetrator (MOP).

The 30,000-pound MOP can only be delivered by the B-2 Spirit stealth bomber, which U.S. Strategic Command has previously confirmed has been forward deployed to Naval Support Facility Diego Garcia in the Indian Ocean. The MOP was likely used in strikes on Yemen in October, under President Joe Biden, to destroy underground weapons storage facilities and command bunkers operated by the Houthis.

But given the physical challenges involved, there is no guarantee that such an operation would succeed. Military planners have floated more alarming ideas — such as using a nuclear weapon to eliminate the site — but Trump has rejected such extreme plans, according to The Guardian.

While there is little doubt that Iran is intent on acquiring the ability to make nuclear weapons, there is as yet no evidence that it is on the brink of deploying one.

Grossi, the IAEA chief, pointed out that while Iran was conducting activities in violation of the NPT, this was not clear evidence a bomb was being built: “We have not seen elements to allow us, as inspectors, to affirm that there was a nuclear weapon that was being manufactured or produced somewhere in Iran.”

Some U.S. officials also made conservative assessments, including Director of National Intelligence Tulsi Gabbard, who in March testified to Congress that American intelligence “continues to assess that Iran is not building a nuclear weapon, and Supreme Leader Khamenei has not authorized the nuclear weapons program that he suspended in 2003.” (Gabbard has reportedly been sidelined by Trump as he weighs attacking Iran.)

Iran has sought a nuclear weapon for decades, and debates about how close it is to acquiring one go back just as far. Compilation clips of Israeli Prime Minister Benjamin Netanyahu giving speeches dating back to 1996 warning that Iran was on the brink of getting the Bomb have become a regular feature on television news.

Whether or not Tehran’s nuclear program is an imminent threat requiring immediate action, ultimately the root cause of Israel’s war is the belief that Iran is an existential threat. In the wake of the Oct. 7, 2023 attacks by Hamas — a key Iranian proxy — Israel made it clear that it would not be constrained in defending itself. Netanyahu has actively sought to destroy the proxies of its chief enemy.

Since then, Hamas has been shattered in Gaza, Hezbollah has been decapitated in Lebanon, the pro-Iranian regime of Bashar al-Assad in Syria has fallen, and the United States has expended billions of dollars in advanced munitions degrading the Houthis’ military capabilities in Yemen.

Still, Iran has never looked as weak as it does now, and that is why Israel has been targeting not just Tehran’s nuclear program, but the very structures and personnel that make up the Islamic Republic’s oppressive regime.

As the two countries trade missiles and bombs and casualties mount, Israeli officials have begun openly calling for the destruction of the Islamic Republic of Iran’s theocratic government, known in Persian simply as the “System.”

Visiting a hospital outside Tel Aviv where an Iranian ballistic missile struck on Thursday, Israeli Defense Minister Israel Katz claimed Iran’s supreme leader, Ayatollah Ali Khamanei, had personally ordered the attack.

“He considers the destruction of the state of Israel to be a goal… Such a man can no longer be allowed to exist,” Katz said. Iran denied targeting the hospital, saying it was only attacking military facilities.

In the U.S., Republican hawks have also taken up the call for action beyond targeting nuclear sites.

“One of the greatest gifts we could give our children or grandchildren would be to stop or destroy the nuclear capabilities of Iran,” said Sen. Steve Daines (R-Mont.), adding that he hoped to see the downfall of the Iranian government. “Once this regime topples, this is a reset for the Middle East, and a reset for the world.”

“It is time for regime change, and I believe that this president should be given a fair amount of leeway to effect that,” said Sen. Thom Tillis (R-N.C.).

“Regime change” is a phrase that doesn’t sit well these days with the American public, who largely oppose direct military involvement in Iran. It also unsettles non-interventionists within Trump’s cabinet, like Gabbard and Vice President J.D. Vance, who posted an equivocal statement on Tuesday saying “[Trump] may decide he needs to take further action to end Iranian enrichment. That decision ultimately belongs to the president. And of course, people are right to be worried about foreign entanglement after the last 25 years of idiotic foreign policy.”

Certainly “idiotic foreign policy” covers a lot of ground, but Vance undoubtedly has foremost in his mind the non-existent Weapons of Mass Destruction used as a pretext to invade Iraq in 2003, the incompetence at the outset of its occupation, and the ensuing sectarian bloodshed that killed 4,507 Americans and 110,600 Iraqis between 2003 and 2009.

Internal divisions within the MAGA movement over military action against Iran have created their own civil war. Many within the Trump Cabinet are wary that — despite the near universal acknowledgment that the war in Iraq was a debacle — the Iran hawks in the GOP have never truly forsaken their neo-conservative past, and remain convinced that the Middle East can be shaped to America’s liking through force of arms.

The non-interventionists themselves have become targets for the Iran hawks, with Gabbard in particular drawing a lot of flak. One analyst from the America First Policy Institute told the BBC that “she was the one cooking the intelligence books on what Iran was doing.” When asked about Gabbard’s testimony to Congress, the president told reporters: “I don’t care what she said, they were very close to having [a nuclear weapon].”

Regardless of how the debate evolves inside MAGA, as Vance pointed out, it is Trump alone who will make a decision.

Israel has tried to make it easy and palatable for the U.S. to consider action, by destroying air defenses and dismantling much of Iran’s medium-range ballistic missile forces, capable of striking Israel or even Europe.

Iran continues to launch ballistic missiles against Israeli cities. Dozens have been killed in Israel thus far, while one human rights group says the death toll in Iran from Israeli strikes is over 600, with thousands wounded.

Tehran so far has not been able to carry out the kind of massive saturation attack that many analysts feared, overwhelming missile interceptors and air defenses by sheer volume of missiles and drones. Grajewski says that is largely because of disruptions to command and control caused by the targeted killings of senior commanders, and that Israel has been hunting mobile missile launchers and the hardened sites where Iran stores its medium-range ballistic missiles.

But much of the country’s short-range ballistic missile and drone arsenal remains intact — and it is these that could be used to strike U.S. military forces and facilities in the region.

Iran is not its proxies. With a large population, mature political institutions, aggressive internal security services, nearly a million soldiers in its military services, and advanced missile and drone technology, its ability to strike at its opponents remains formidable. “Iran does have these really dangerous escalation opportunities that they could use,” Grajewski says.

Trump’s current path of coercive diplomacy in tandem with Israeli military action may yield results, but for now Iran is refusing to back down.

Iran is “ready to consider diplomacy once again, once the aggression is stopped,” Foreign Minister Abbas Araghchi said at a press conference in Geneva on Friday, after an emergency summit with European diplomats. “I make it crystal clear that Iran’s defense capabilities are non-negotiable.”

If the U.S. does decide to intervene militarily, Iran will almost certainly respond in kind.

Netanyahu spoke about Trump with reporters on a visit to a site that had been struck by a ballistic missile. “I trust his judgment,” he said. “He’s a tremendous friend to Israel, and to the Israeli people. We’re both committed to making sure Iran will not have a nuclear weapon.”

Netanyahu’s confidence in Trump is more than just flattery. In December 2017, this reporter was in Jerusalem when the U.S. announced it was recognizing the ancient city as the capital of Israel — a move that previous American presidents had long shied away from as being unnecessarily inflammatory, and undermining efforts to achieve a “two-state solution” with the Palestinians through dialogue.

Amid daily clashes between Israeli security forces and Palestinian protesters in response, a meme began to spread among Israelis, based on an iconic photograph from the 1967 Six-Day War. In that conflict, Israel defeated a coalition of Arab states and captured the Sinai Peninsula, the Golan Heights, the Gaza Strip, and the West Bank — including East Jerusalem and its holy sites.

The original photo is of soldiers from Israel’s 35th Paratroopers Brigade reaching the Western Wall — among the holiest sites in Judaism. The meme circulating 50 years later had Donald Trump’s face photoshopped over the middle soldier. There was no doubt that the American president was a champion of Israel.

There is little question that he remains so today. But as the U.S. urgently debates whether to join Israel’s military campaign, there is skepticism that doing so will solve the problem.

“What’s clear is that there may be some setbacks in terms of Iran’s ability to weaponize or ability to use some of the fissile material because of Israeli air superiority,” Grajewski says. “But striking Fordow is not going to eradicate the Iranian nuclear program.”