Israel redeploys troops from Gaza to its borders as its focus turns to Iran.

Hours earlier, Iran’s supreme leader, Ayatollah Ali Khamenei, had dismissed threats Mr. Trump had made a day earlier and rejected his call for an “unconditional surrender, adding to fears of a wider conflagration in the Middle East.

“Intelligent people who know Iran, the nation and the history of Iran will never speak to this nation in the language of threats, because the Iranian nation cannot be surrendered,” he said in a televised statement, according to Iranian state media. “The Americans should know that any U.S. military intervention will undoubtedly be accompanied by irreparable damage.”

His remarks, on the sixth day of the war, were a defiant response to Israel and to Mr. Trump, who has signaled that the United States was weighing whether to join Israel’s bombing campaign against Iran’s nuclear program. Both the United States and Israel say that Iran must not be allowed to have atomic bombs; Iran insists that it is not trying to develop such weapons.

Mr. Trump said that Iran wanted to negotiate and that it was not too late for talks, but criticized the leadership in Tehran for not acting sooner.

“Why didn’t you negotiate with me two weeks ago? You could have done fine,” he said, ominously concluding, “You would have had a country."

In fact, Iran had entered into negotiations with the United States about the future of its nuclear program — it put those talks on hold after Israel began bombing — but had not bowed to White House demands.

Israel has been pressing for the United States to assist in the effort to destroy Iran’s nuclear program, and in particular to use its largest bunker-busting bombs — which Israel does not have, nor the planes capable of delivering them — against Iranian nuclear facilities deep underground.

Mr. Trump has long maintained that he opposes getting involved in foreign wars and has repeatedly expressed hopes for a nuclear deal with Iran. But he said on Tuesday that “our patience is wearing thin,” and also cited the possibility of killing Ayatollah Khamenei.

Israel continued to pummel Iran on Wednesday, launching fresh strikes on Tehran. Earlier in the day, Israel’s military said more than 50 Israeli warplanes had attacked targets across the Iranian capital, including a nuclear centrifuge plant. The Iranian authorities did not immediately comment on the claims, though the U.N.’s nuclear watchdog said that two centrifuge production facilities had been hit.

Iran fired about 30 ballistic missiles at Israel in two barrages after midnight and two waves of drones on Wednesday morning, but most of the missiles and all the drones were intercepted, Israel said. There were no immediate reports of casualties, and Iran’s missile salvos appeared to be limited compared with earlier attacks.

Here’s what else to know:

• Threat of retaliation: Iranian officials have said that if the United States enters the war, Iran will attack American bases in the region. Iran has prepared missiles for these possible strikes, according to U.S. officials who have reviewed intelligence reports.

• Shift in strategy: In Iran, Israel is carrying out the kind of broad and brazen attack that it long threatened but never dared to enact. The campaign reflects an extraordinary shift in Israeli military doctrine since Hamas, Iran’s Palestinian ally, attacked the country in October 2023. That change has redrawn the power dynamics in the Middle East, unraveled Iran’s regional alliance and enshrined Israel as the dominant military force in the region.

• Stranded travelers: The first flights carrying Israelis stranded abroad landed at Ben Gurion International Airport on Wednesday as part of a wave of special transports to bring citizens home. Thousands of international tourists have been unable to leave Israel since the country’s airspace was closed to civilian flights last week.

• Internet disrupted: Amid severe disruptions to internet services in Iran, the country’s state broadcaster urged people to remove WhatsApp from their phones, claiming that the messaging app was collecting user information and sending it to Israel. WhatsApp has rejected the allegations.

Israel long feared that striking Iran’s nuclear facilities would prompt an immediate and overwhelming response from Tehran’s network of allies and proxy militias across the region. Of particular concern was Hezbollah, the politically powerful Lebanese armed group, whose ranks of armed fighters and arsenal of rockets Iran had helped build up, in part as a deterrent against an Israeli attack.

But over the past year and a half, Iran’s allies have been severely weakened or eliminated. The war in Gaza has decimated Hamas, the Iran-allied group that led the Oct. 7, 2023 assault on Israel.

After months of cross-border attacks by Hezbollah in support of Hamas, the Israeli military last year killed much of Hezbollah’s leadership, including its longtime leader, Hassan Nasrallah; killed or wounded many of its fighters; and depleted its weapons stockpiles.

Hezbollah so far has stayed out of the current round of fighting between Israel and Iran, and the Lebanese government has warned the group not to get involved.

The Iranian-backed government of Bashar al-Assad in neighboring Syria fell last December, toppled by Islamist rebels who are not friendly to Tehran. Almost immediately, Israeli forces bombed Syrian weapons caches and advanced into southern Syria to create a buffer zone, arguing that Mr. Assad’s departure had created a dangerous vacuum on their border.

Across Washington, Jerusalem and Tehran, millions of people waited to see if Mr. Trump would plunge the United States into the war between Israel and Iran. Israel has asked the United States to use its more advanced military capability to help further cripple Iran’s nuclear program.

Just a day earlier, Mr. Trump issued bellicose threats to Iran, telling the more than 10 million people living in Tehran, the capital, to evacuate. In a separate post on social media, he cited the possibility of killing the country’s supreme leader, Ayatollah Ali Khamenei.

On Wednesday, Mr. Trump blamed Iran’s leaders for the violence, reiterating that they should have negotiated sooner with the United States to reach a nuclear deal that might have prevented Israel from beginning its strikes. He said Iran now wants to negotiate.

“Why didn’t you negotiate with me before all this death and destruction?” Mr. Trump said. “Why didn’t you negotiate? I said to the people, ‘Why didn’t you negotiate with me two weeks ago? You could have done fine. You would have had a country.’”

But in response to a question about whether it was now too late to negotiate, Mr. Trump said, “Nothing’s too late.”

On Monday, Mr. Trump left a meeting of the leaders of the Group of 7 nations in Canada a day early to return to Washington to deal with the conflict between Israel and Iran. On Tuesday, he met with his national security team at the White House.

Mr. Trump’s public consideration of joining Israel’s military campaign has sharply divided the Republican Party, and left some of the president’s most prominent supporters in disbelief. Tucker Carlson, the former Fox News host, and Stephen K. Bannon, a former top aide to Mr. Trump, have both warned the president about allowing the United States to be drawn into the conflict. Mr. Trump shot back, describing Mr. Carlson as “kooky” on social media.

Vice President JD Vance has sought to reassure the anti-interventionist part of the party, writing his own lengthy social media post on Tuesday.

“Of course, people are right to be worried about foreign entanglement after the last 25 years of idiotic foreign policy,” Mr. Vance wrote on X. “But I believe the president has earned some trust on this issue. And having seen this up close and personal, I can assure you that he is only interested in using the American military to accomplish the American people’s goals.”

The Israeli military also struck laboratories that work to convert uranium gas back into a metal — one of the last stages of building a weapon — at a complex outside the ancient capital of Isfahan where Iran’s most likely repository of near bomb-grade nuclear fuel is stored. The stockpile has so far been spared from attack.

Iranian missile capability has also been degraded by the strikes. Israel said it struck 12 missile launch sites and storage facilities on Tuesday alone.

See a more detailed look at the damage to strategic infrastructure at the link below.

Two buildings were also destroyed at a workshop in Karaj, a city northwest of the capital, where other components were manufactured, the I.A.E.A. added. The agency said it had previously monitored both sites under a 2015 nuclear agreement that Iran signed with the Obama administration and other governments.

The Israeli military said earlier that it had deployed more than 50 warplanes across Tehran overnight to attack weapons production facilities and a centrifuge plant that it said were being used to enrich uranium and manufacture parts used to develop weapons. A military official later said that about 20 targets were hit.

Israel launched a military campaign last week that it said was designed to prevent Iran from building a nuclear bomb, attacking military infrastructure and government buildings and assassinating Iranian nuclear scientists and military commanders.

On Friday, the Israeli military targeted the nuclear site at Natanz, where Iran produces most of its nuclear fuel. The I.A.E.A. initially said that the attack had destroyed the aboveground part of the fuel enrichment plant, including electricity infrastructure. The agency said on Tuesday that it had also identified “direct impacts” on the underground enrichment halls.

Iran says that its nuclear program is solely for peaceful purposes and has consistently denied that it plans to build a bomb. Tehran has also given no indication that it intends to abandon its atomic industry, and it has launched a wave of deadly missiles and drones at Israel in retaliation.

Last Thursday, the I.A.E.A. said that Iran was not complying with its nuclear nonproliferation obligations, the first time the agency has passed a resolution against the country in 20 years.

“Intelligent people who know Iran, the nation and the history of Iran will never speak to this nation in the language of threats, because the Iranian nation cannot be surrendered,” Ayatollah Khamenei said in a televised statement on Wednesday, according to Iranian state media. “The Americans should know that any U.S. military intervention will undoubtedly be accompanied by irreparable damage.”

The statement on the sixth day of the war came just hours after Israel said it launched a fresh wave of strikes on the Iranian capital.

Overnight, the ayatollah had issued a defiant call to arms, saying in a post on social media that “the battle begins.”

In a post on Truth Social on Tuesday, Mr. Trump said that the United States knew where Ayatollah Khamenei was “hiding,” and said that its forces do not plan to kill him for now. Prime Minister Benjamin Netanyahu of Israel has also spoken in recent days of a potential strike on the Iranian leader.

Ayatollah Khamenei, who has led Iran for more than three decades and is at the heart of Iran’s hard-line foreign policy, did not directly address the threats against his life in his statement or on social media.

He has played a key role in positioning Iran as a counterweight to American, Israeli and Saudi influence across the Middle East. Ayatollah Khamenei has also consolidated control of Iran’s political, military and security apparatus, and crushed dissent to shore up his position as the country’s ultimate decision maker.

Hwaida Saad contributed reporting

WhatsApp, in a statement on Tuesday, said the allegations were false.

“We’re concerned these false reports will be an excuse for our services to be blocked at a time when people need them the most,” the statement said. “All of the messages you send to family and friends on WhatsApp are end-to-end encrypted, meaning no one except the sender and recipient has access to those messages, not even WhatsApp.”

Internet services across Iran have been suffering severe disruptions, according to Iranian officials, experts and citizens, who say the government is likely restricting access to limit the spread of information about strikes and for fear of Israeli cyberattacks.

WhatsApp, which is owned by Meta, is one of the world’s most popular messaging services. It said in the statement that it does not track users’ precise location, nor does it monitor the messages people are sending one another. “We do not provide bulk information to any government,” the statement said.

End-to-end encryption makes it very hard for law enforcement and spy agencies to get access to people’s digital communications.

Israel’s massive, ongoing assault on Iran highlights an extraordinary shift in Israeli military doctrine since Hamas, Iran’s Palestinian ally, attacked the country in October 2023. It is a change that has redrawn the power dynamics in the Middle East, unraveled Iran’s regional alliance and enshrined Israel as the dominant military force in the region.

Having given Hamas years to prepare for the Oct. 7 attack, Israel reversed course afterward to unleash one of the most destructive campaigns in recent warfare. It then assassinated most of Hezbollah’s leadership and decimated large parts of southern Lebanon. Now, in Iran, it is carrying out the kind of broad and brazen attack that it long threatened but never dared to enact.

“We are changing the face of the Middle East,” said Prime Minister Benjamin Netanyahu of Israel during a press briefing on Monday. “And this could lead to far-reaching changes within Iran itself,” he added.

For now, that second claim remains unproven. The Israeli military campaign has weakened Iran, but it has not yet destroyed the country’s nuclear program or collapsed its government, and it may still fall short of both. The war could also devolve into an intractable quagmire with no exit strategy or offramp.

Mr. Netanyahu’s broader point is harder to contradict. Hamas is no longer a threat to Israel. Hezbollah’s influence over Lebanon — let alone the danger it poses to Israelis — is much diminished. The government in Syria, a pillar of Iran’s regional alliance, was overthrown last December, in part because Hezbollah could no longer come to its aid.

These tectonic shifts also speak to a vast change within the Israeli psyche and strategic outlook since Hamas’s attack in October 2023.

For Israel’s critics, the attack was the inevitable consequence of the country’s blockade of Gaza, occupation of the West Bank, and failure to resolve the Palestinian conflict through diplomatic concessions. Many Israelis have drawn the opposite conclusion: They believe that the October attack — the deadliest in Israeli history — stemmed from Israel’s failure to pre-emptively and decisively defeat its enemies.

“In the 20 years before Oct. 7, we allowed threats to develop beyond our borders, trusting that our intelligence would give us prior warnings of any attack,” said Maj. Gen. Amos Yadlin, a former head of Israeli military intelligence.

“The trauma of Oct. 7 completely changed that mind-set and made us willing to take risks that we didn’t take in the past,” General Yadlin said. “We will no longer wait to be attacked, and we will not wait to be surprised.”

The approach echoes Israel’s strategic outlook in the early decades of its existence, when it often acted more swiftly and decisively to remove threats on its borders, General Yadlin said. The clearest example was in June 1967, when Israel pre-emptively attacked Egypt after the Egyptian military moved troops toward the Israeli border.

“As Egypt massed troops on our southern border, we did not wait to be surprised,” General Yadlin said. “Now, we are reviving that doctrine.”

Israel’s new approach is the culmination of months of re-evaluation, during which the military’s confidence — crushed by the failures of Oct. 7 — was gradually restored.

While Israel’s approach to Hamas was immediately wrathful, the country was initially wary of taking on Hezbollah and Iran. Mr. Netanyahu called off a pre-emptive attack on Hezbollah in the first week of the war in 2023, amid fears that Israel would struggle to maintain a multi-front war against the Iran-led alliance.

For nearly a year, Israel fought only a low-level border conflict with Hezbollah. Despite increasing clashes with Tehran in 2024, Israel limited its strikes on Iran to avoid an all-out conflict.

Israel’s approach began to change last September, when a sequence of unexpected moves allowed Israel to decimate much of Hezbollah’s senior leadership.

That increased Israel’s confidence and prompted its leaders to order a more decisive assault on the group. Troops invaded southern Lebanon and the air force killed Hezbollah’s secretary general, Hassan Nasrallah.

Israel then severely weakened Iran’s air defense systems and successfully repelled massive barrages of Iranian missiles, giving Israel greater confidence in its offensive and defensive abilities. More than a year after Oct. 7, Israeli leaders finally concluded that they had a rare window of opportunity to mount a decisive blow against Iran’s nuclear program.

Though Israel’s new approach has undercut Iran’s regional influence, it has done little to resolve Israel’s oldest and most intractable problem: the Israeli-Palestinian conflict.

In Gaza, Israel’s retaliation has led to widespread destruction and bloodshed, reinstating a fearsome sense of Israeli might and reducing Hamas’s threat for a generation.

But the conflict has provided no clear long-term trajectory for either Gaza or the wider Palestinian question. Mr. Netanyahu has consistently ignored opportunities to end the war, balking at the idea of either leaving Hamas’s remnants in charge or allowing other Palestinian groups to take over.

“Instead, we are left with only bad options,” said Tzipi Livni, a former Israeli foreign minister. “Either occupation or chaos, rather than a diplomatic process involving moderate regional and Palestinian stakeholders that could change the reality on the ground for both Palestinians and Israelis.”

A similarly aimless dynamic could yet emerge in Iran, analysts said, if the Israeli leadership fails to clearly define its goals there and set an exit strategy.

For now, Israeli officials hope the United States will join the attack and help Israel destroy Iran’s nuclear enrichment facilities. If the United States stays away, and if Iran refuses to stop the enrichment by choice, it is unclear whether Israel’s forceful new doctrine will achieve the kind of game-changing outcomes that many Israelis desire.

“One wonders whether effective military performance is matched by a sober political vision,” said Nimrod Novik, a former senior Israeli official and a fellow at Israel Policy Forum, a research group in New York. “Or, like in Gaza, we are left without an endgame. Time will tell.”

Johnatan Reiss and Gabby Sobelman contributed reporting.

The first flight, by the national airline El Al, came from Cyprus, a popular destination for Israeli tourists. Israeli television showed the passengers, after being swiftly processed, quickly leaving on trains and shuttle buses because of the threat of an Iranian missile strike at Ben Gurion.

“I want to say is that we will remain in Tehran, we will not leave this land. Even if we have to sacrifice every ounce of our blood, like a soldier, we will fight,” said Mr. Khomeini. “The enemy has made a massive mistake if it thinks it can dislodge this revolution.”

An even bigger mistake, Mr. Khomeini said, would be for President Trump to enter the war and attack the Fordo nuclear site. On Tuesday, Mr. Trump posted a series of messages on social media, one of which called for Iran’s “unconditional surrender.” He also met with his National Security Council as evidence mounted that the United States was considering joining Israel’s bombing campaign to damage Iran’s nuclear capabilities. A day earlier, Mr. Trump had warned residents of Tehran, a city of more than 10 million people, to evacuate in a social media post. Many residents of Tehran have tried to heed his call.

“Iran will respond in a different way if this happens,” Mr. Khomeini said, in reference to the United States becoming more involved in the conflict. The war would spread, and the region would descend further into chaos, he said.

Mr. Khomeini lives in the city of Qom, about 100 miles south of Tehran, where he attends Shia theological seminary. He is the grandson of Mr. Khomeini’s son, Ahmad, and in the past few years has identified with the reformist faction of the government. He campaigned for the reformist candidate, Masoud Pezeshkian, who won the presidential election nearly a year ago.

Mr. Khomeini said that he typically spends weekends in Tehran and was there on Friday — the Iranian weekend — when Israel first attacked. He said he had remained in the capital, consulting with a tight loyal circle of younger government officials. He did not want to retreat to a bunker, he said.

On Tuesday night, a crowd of government supporters gathered at Palestine Square in central Tehran, waving flags and pledging fierce revenge against Israel. A digital countdown clock at the square shows what it claims is the time left until Israel’s demise. Mr. Khomeini said he heard about the gathering and spontaneously decided to participate despite a new round of Israeli strikes in the Tehran area.

Israel has assassinated at least 10 of Iran’s highest-ranking military commanders since Friday. On Tuesday, Israel said it had killed the new top military commander, Maj. Gen. Ali Shadmani, in a strike, days after he was appointed. Iran did not comment on Israel’s claim.

But that has not deterred the young Mr. Khomeini. Part of his great-grandfather’s legacy, he said, was to show the public and the enemies that he was not afraid. “I’m one person, and I want to stand by the people,” he added.

He said he understood that some Iranians “are angry at the establishment, are upset and have negative views of the government, have different beliefs” from the republic his great-grandfather founded, but he called on his people to always choose Iran. Mr. Khomeini said he named his 2-year-old daughter Iran.

Iranians have staged nationwide demonstrations, most recently in 2022 that were led by women and young girls following the death of Mahsa Amini, a 22-year-old who died in the custody of the country’s morality police on allegations of violating hijab rules, which mandate that women and girls cover their hair and bodies. The government has brutally crushed the protests, blocked reforms and jailed and killed hundreds of protesters. The demonstrators have chanted “Death to the dictator” and participated in daily acts of collective civil disobedience, like women not wearing hijabs in public.

Iranian officials have long been concerned that a war with Israel or the United States would destabilize the country, deepen economic woes and spark a new domestic uprising. The supreme leader, Ayatollah Ali Khamenei, who succeeded Mr. Khomeini’s great-grandfather, conceded to nuclear negotiations with the United States in March to avoid the risk of fighting a war on two fronts, against external enemies and domestic dissent.

Asked what he thinks Ayatollah Khomeini would say to him about the current war, the young Mr. Khomeini replied, “remain together, stay united; if you do, no enemy can win over you.”

Fears of a wider war are growing among American officials as Israel presses the White House to intervene in its conflict with Iran. If the United States joins the Israeli campaign and strikes Fordo, a key Iranian nuclear facility, the Iranian-backed Houthi militia will almost certainly resume striking ships in the Red Sea, the officials said. They added that pro-Iranian militias in Iraq and Syria would probably try to attack U.S. bases there.

Other officials said that in the event of an attack, Iran could begin to mine the Strait of Hormuz, a tactic meant to pin American warships in the Persian Gulf.

Commanders put American troops on high alert at military bases throughout the region, including in the United Arab Emirates, Jordan and Saudi Arabia. The United States has more than 40,000 troops deployed in the Middle East.

Two Iranian officials have acknowledged that the country would attack U.S. bases in the Middle East, starting with those in Iraq, if the United States joined Israel’s war.

Iran would also target any American bases that are in Arab countries and take part in an attack, the two officials said.

“Our enemies should know that they cannot reach a solution with military attacks on us and will not be able to force their will on the Iranian people,” Iran’s foreign minister, Abbas Araghchi, said in a statement on Monday. Mr. Araghchi told his European counterparts in phone conversations that if the war spread, the blame would be on Israel and its main supporters, according to a summary of the calls provided by Iran’s foreign ministry.

U.S. officials said Iran would not need much preparation to attack American bases in the region. The Iranian military has missile bases within easy striking range of Bahrain, Qatar and United Arab Emirates.

The prospect of U.S. forces joining the war has increased in recent days as Israel has continued its campaign, and Iran has launched waves of missiles at Israel in response.

It is not clear how much damage a strike on Fordo would do to Iran’s nuclear capabilities or how long it would delay the development of a weapon. Iran’s current stockpile of enriched uranium is also hidden in tunnels at different locations in the country.

Several American officials said that Israel would need U.S. help to more significantly damage Iran’s nuclear program.

American assistance could include providing air cover for Israeli commandoes who go into Iran on the ground. But, officials said, the more probable outcome is a strike by U.S. B-2 stealth bombers armed with the Massive Ordnance Penetrator, a weapon that theoretically has the ability to bore into the mountain that shelters the underground Fordo facility.

Any strike on Fordo by the United States or with U.S. assistance would prompt Iran and its allies to retaliate.

Iran and its allies have been able to harm Americans in the past. The Houthis curbed their attacks after the Trump administration stepped up strikes on them. But in recent years they have repeatedly tried to strike American warships and have hit commercial shipping. In January 2024, an Iranian-backed militia carried out a drone attack on a U.S. base in Jordan near the Syrian border that killed three American soldiers.

American intelligence agencies have long concluded that Iran was close to being able to make a nuclear weapon but had not decided whether to do so. If Iran decided to make a weapon, it would be less than a year away from being able to field one. A crude, more basic nuclear bomb could possibly be constructed more quickly.

President Trump has repeatedly said he will not allow Iran to obtain a nuclear weapon. On Tuesday, he called for Iran’s unconditional surrender.

But the Israeli attacks may have changed Iran’s calculus. U.S. officials skeptical of Israel’s campaign said on Tuesday that it has probably convinced Tehran that the only way to prevent future attacks would be to develop a full nuclear deterrent.

Some of those officials said that if Iran is likely to pursue a nuclear weapon no matter what, pressure could increase on the Trump administration to strike.

But critics of aggressive, militaristic foreign policy said it was not too late for the United States to turn back.

“It is never too late not to start a war,” said Rosemary Kelanic, the director of the Middle East program at Defense Priorities, a think tank that advocates a restrained foreign policy.

Ms. Kelanic acknowledged that Israel’s strike had given Iran an incentive to potentially develop a nuclear weapon. But she added that the incentive would “multiply dramatically if the United States joins the war.”

“Once you get involved, man, it’s really hard to step back,” she said. “You are just going to go all in.”

Adam Goldman contributed reporting.

Senator Tim Kaine, Democrat of Virginia, on Monday introduced a similar resolution.

Both efforts face long odds on Capitol Hill given Republicans’ reluctance to challenge Mr. Trump’s power, but with some lawmakers in both parties openly resisting further U.S. involvement, they are likely to prompt a vibrant debate. The measures enjoy a special status that will compel Congress to vote on them one way or the other in the coming days.

Still, Speaker Mike Johnson has, so far, been successful in deflecting efforts to force Republican members to take any vote that would require them to challenge Mr. Trump’s authority, and he could seek a procedural solution that would allow him to circumvent a vote on a war declaration.

The move in the House quickly drew detractors, including Representative Mike Lawler, Republican of New York, who posted on social media that “If AOC and Massie are a yes, that’s a good bet that I’ll be a no.” He was referring to Representative Alexandria Ocasio-Cortez of New York, who was among the Democrats backing the measure.

And in the Senate, defense hawks cheered Mr. Trump’s bellicose posture.

Senator Lindsey Graham, Republican of South Carolina, on Tuesday reiterated his stance that he supports U.S. involvement in the conflict against Iran.

“Yeah, I want us to go all in to help Israel destroy their nuclear programs,” he said, adding that he had spoken to Mr. Trump Monday evening about his views.

When asked what role Congress should have in authorizing offensive strikes in Iran, Senator Bernie Moreno, Republican of Ohio, deferred to Mr. Trump.

“I have total faith and confidence in the president of the United States,” he said in an interview on Tuesday.

While Congress has not issued a formal declaration of war since World War II, it has authorized the use of military force through a series of resolutions, most notably following the Sept. 11, 2001, attacks.

That resolution granted President George W. Bush the authority to use military force against those responsible for the attacks and any groups that harbored them. The following year, Congress passed another resolution authorizing the use of force against Iraq, citing concerns about weapons of mass destruction.

The pair of authorizations has been used to justify a wide range of military actions since then, including the Obama administration’s campaign against ISIS in 2014. In recent years, lawmakers from both parties have criticized the broad scope of these measures, arguing that they give the executive branch too much power over decisions that should rest with Congress.

More recently, the debate over the scope of presidential war powers was reignited during Mr. Trump’s first term after the killing of Gen. Qassim Soleimani of Iran. The administration shifted its legal rationale multiple times, initially citing the 2002 authorization as basis for the argument that Iran, and General Soleimani, posed “imminent threats” before later contradicting that position in a report to Congress.

A 2023 effort to repeal the authorizations used to justify the strike, led by Mr. Kaine, stalled after being sent to the House but drew bipartisan support in the Senate, including from then-Senator JD Vance of Ohio.