Before the U.S. launched its military offensive against Iran on Saturday, President Trump had expressed frustration with the progress of talks about Iran’s nuclear program and deployed an “armada” to the Middle East. But said he had not said much about the reasons why the U.S. would conduct a bombing campaign against the regime.
Mr. Trump on Monday articulated the reasons the U.S. launched its attack on Iran, bombing over 1,000 targets in the opening days of what he has said he expects to be a weeks-long war.
In his first live public remarks on the operation, he offered four reasons for the campaign:
- Destroying Iran’s missile capabilities;
- Annihilating Iran’s navy;
- Preventing Iran from developing nuclear weapons;
- Ensuring the regime can’t continue to arm, fund or direct “terrorist armies” outside its borders.
A senior administration official said the operation would continue until all four objectives are achieved. The president has said he expects the war to last four or five weeks, but administration officials say the operation could be completed sooner or later than the timeline estimated by Mr. Trump.
Here is what the president and other top officials have said about why the U.S. is striking Iran:
Imminent threat posed by Iran’s ballistic missiles
President Trump said Saturday, hours after the offensive began, that his objective was “eliminating imminent threats from the Iranian regime.”
Iran’s “menacing activities directly endanger the United States, our troops, our bases overseas and our allies throughout the world,” Mr. Trump said in a brief address he posted on Truth Social.
He said that after the strikes on Iranian nuclear facilities last year, the regime continued “developing long range missiles that can now threaten our very good friends and allies in Europe, our troops stationed overseas, and could soon reach the American homeland.”
But a Defense Intelligence Agency assessment from last year indicated that Tehran would not have intercontinental ballistic missiles capable of reaching the U.S. until 2035.
On Saturday, senior Trump administration officials told reporters that they “had indicators” that Iran could potentially use conventional missiles “preemptively, but if not, simultaneous” to any U.S. actions against the regime. The president “was not going to sit back and wait to get hit first” and if he had, the “amount of casualties and damages would be substantially higher” than if the U.S. acted preemptively, they said.
Defense Secretary Pete Hegseth indicated Monday that the justification for the offensive was Iran’s “swelling arsenal of ballistic missiles and killer drones,” which he said they were using to “create a conventional shield for their nuclear blackmail ambitions.”
Secretary of State Marco Rubio offered a slightly different rationale on Monday, telling reporters the Trump administration decided to attack because Israel was planning to strike Iran, and “we knew that that would precipitate an attack against American forces.” For that reason, he said, the U.S. chose to strike Iran “preemptively” to take out many of its missiles.
Sen. Mark Warner of Virginia, the top Democrat on the Senate Intelligence Committee, told CNN’s “State of the Union” Sunday, “I saw no evidence that Iran was on the verge of launching any kind of preemptive strike against the United States of America.”
Warner is one of the “Gang of Eight” members of Congress who was briefed by Rubio before the operation began. After another briefing by Rubio on Monday, Warner said he didn’t believe Iran’s missiles posed an imminent threat to the U.S. — though they did pose a significant threat to Israel.
“This is still a war of choice that has been acknowledged by others was dictated by Israel’s goals and timelines,” Warner said.
Iran’s nuclear program
Negotiations over Iran’s nuclear program had been underway for weeks. During his State of the Union address last week, Mr. Trump laid down a red line.
“My preference is to solve this problem through diplomacy, but one thing is certain: I will never allow the world’s No. 1 sponsor of terror — which they are by far — to have a nuclear weapon,” he said. “Can’t let that happen.”
On Friday, hours before the strikes began, the Omani foreign minister, who was the mediator of those talks, said “substantial progress” was being made and a deal was “within our reach.” He told CBS News’ Margaret Brennan that Iran had agreed it will “never, ever have … nuclear material that will create a bomb.”
But the same day, the president told reporters he wasn’t happy with how the talks were progressing. “I’m not happy with the fact that they’re not willing to give us what we have to have,” he said. “I’m not thrilled with that.”
Mr. Trump demanded Iran stop enriching uranium. Iran has long refused to give up its enrichment capabilities, insisting the program is intended for peaceful purposes, though in recent years, Iran has enriched uranium to near weapons-grade level, well beyond the purity levels required for most peaceful uses.
“They want to enrich a little bit. You don’t have to enrich when you have that much oil,” Mr. Trump said.
Senior administration officials indicated they did not believe Iran was negotiating in good faith. They said that “it was clear to us that they were in the throes of rebuilding all that had been destroyed in Midnight Hammer,” the June operation that struck the regime’s nuclear facilities, and that Iran’s intent “was to preserve their ability to do enrichment, so that over time, they could use it for a nuclear bomb.” They concluded the president “had no choice” but to act.
In announcing the attack on Iran early Saturday, Mr. Trump emphasized that “it has always been the policy of the United States, in particular, my administration, that this terrorist regime can never have a nuclear weapon.”
He said Iran had “rejected every opportunity to renounce their nuclear ambitions, and we can’t take it anymore.”
The 2025 Worldwide Threat Assessment published by the Defense Intelligence Agency said, “Iran almost certainly is not producing nuclear weapons, but Iran has undertaken activities in recent years that better position it to produce them, if it chooses to do so.”
Rubio told reporters last week Iran was not currently enriching uranium.
On Sunday, in a second video, the president said the military operation is “necessary to ensure that Americans will never have to face a radical, bloodthirsty terrorist regime armed with nuclear weapons and lots of threats.”
Destroying Iran’s navy
In his first Truth Social post of the day Sunday, Mr. Trump wrote that he’d been told “we have destroyed and sunk 9 Iranian Naval Ships, some of them relatively large and important.” And, he added, “We are going after the rest — They will soon be floating at the bottom of the sea, also!” The president said that another attack had destroyed the regime’s naval headquarters.
By Monday afternoon, CENTCOM said that all 12 of the ships the Iranian navy had in the Gulf of Oman had been destroyed. The regime had relied on its navy to throttle ship traffic through the Strait of Hormuz — a crucial passageway for transporting about 20% of the world’s oil and liquified natural gas.
The Iran war has brought oil tanker traffic through the strait to a virtual standstill. Shipping giants Maersk and Hapag-Lloyd said they were suspending all shipments through the strait.
Oil prices spiked Monday on concerns that a prolonged disruption of crude supplies in the region could sharply boost energy costs, including U.S. gas prices.
The Iranian Revolutionary Guard Corps announced Monday that the strait would be closed and said it would “set on fire any ship that tries to pass through the Strait of Hormuz.”
“We will not allow a single drop of oil to leave the region,” the IRGC said.
But as energy analyst Kevin Book of Clearview Energy told the AP, “Iran has essentially two ways to close the strait. One is to harass or attack ships, and the other is to lay down mines. And without a navy, both of those things would be difficult.”
Cutting off funding to Iran’s proxy terrorist groups
The president also stated Monday that the offensive was intended to ensure “the Iranian regime cannot continue to arm, fund and direct terrorist armies outside of their borders.”
Iran was designated a state sponsor of terror by the U.S. State Department in 1984. The department’s most recent country report on terrorism, published in 2023, identified the regime as the leading state sponsor of terrorism, “facilitating a wide range of terrorist and other illicit activities in the United States and globally.”
It stated that Iran supports terrorism acts through proxies and partners that include Hezbollah in Lebanon, Ansar Allah (known as the Houthis) in Yemen, Hamas in the Palestinian territories, and groups that operate in Bahrain, Iraq, Syria and elsewhere.
Hamas carried out a terrorist attack on Oct. 7, 2023, that killed 1,200 people in Israel and took 251 hostage, initiating a war with Israel that lasted a little over two years. A ceasefire in Gaza is now in its second phase.
Houthis in Yemen in late 2023 attacked shipping lanes in the Red Sea, “significantly disrupting maritime commerce and global trade,” the report said.
Other groups conducted drone attacks against U.S. forces in Iraq and Syria, the report said, and also noted that Iran’s IRGC Quds Force and Intelligence and Security Ministry supported terrorist recruitment and plotting in Africa, Asia, Europe and the Americas.
In recent years, the Israel Defense Forces carried out a series of fatal strikes on leaders of major Iranian proxy groups, including Hezbollah leader Hassan Nasrallah, key Houthi official Mohammed al-Ghamari and top Hamas leaders Yahyah Sinwar, Mohammed Sinwar and Mohammed Deif.
The IDF called the strike that killed Iran’s Supreme Leader Ayatollah Khamenei “the culmination of a sustained effort to eliminate the senior leadership of the Iranian terror axis.”
Hamas political leader Ismail Haniyeh was also killed in Tehran in a 2024 operation that a U.S. official attributed to Israel, though the Israeli military has not taken responsibility.
Deaths of Iranian protesters and regime change
Regime change is not among the reasons for the military operation listed by Mr. Trump on Monday, but the U.S.-Israeli offensive has targeted dozens of Iran’s top leaders, including Khamenei, who was killed on the first day. While the U.S. has said that Israeli forces carried out that strike, they did so after receiving intelligence about his location from the CIA.
Mr. Trump said Monday that 49 top Iranian leaders had been killed.
In his Saturday video, he urged Iranians to finish what the U.S. and Israel started and overthrow the government.
“Now is the time to seize control of your destiny,” he told the Iranian people. “This is the moment for action. Do not let it pass.”
Amid the Iranian government’s bloody crackdown on protesters in January, in which thousands were killed, Mr. Trump warned of “very strong action” against the regime and told Iranians that U.S. “help is on its way.”
Over the weekend, he told the Washington Post the goal is “freedom for the people” of Iran.
“All I want is freedom for the people,” he said.