June 21, 2025, 5:06 p.m. ET

Elena Shao and Devon Lum

Several U.S. B-2 bombers were deployed west across the Pacific.

Several U.S. Air Force B-2 bombers appeared to be airborne over the Pacific, after having taken off from Whiteman Air Force Base in Missouri. The aircraft can be equipped to carry the 30,000-pound bunker-buster bombs President Trump is considering dropping on the Fordo underground nuclear site in Iran.

Russia

Several B-2s took

off from Whiteman

Air Force Base in

Missouri.

Mongolia

United

States

Turkey

Japan

Pacific Ocean

China

Israel

Iran

Saudi

Arabia

They’ve called

in from over

the Pacific.

Mexico

India

Ethiopia

Their destination may

be Andersen Air Force

Base in Guam.

Colombia

Peru

Indian Ocean

Australia

Several B-2s took off

from Whiteman Air

Force Base in Missouri.

Russia

They’ve called

in from over

the Pacific.

United

States

Japan

China

Israel

Iran

India

Mexico

Ethiopia

Their destination

may be Andersen

Air Force Base in

Guam.

Pacific

Ocean

Indian

Ocean

By Devon Lum and Elena Shao

The B-2 flights were first referenced by air traffic controllers at Springfield-Branson National Airport around 12:18 a.m. Eastern time. Two aircraft later reported their positions over the Pacific via radio communications between 5:59 a.m. and 7:44 a.m. Eastern time.

Some flight trackers said on social media that the aircrafts’ destination may be Guam, which is home to Andersen Air Force Base.

The movement of the planes does not mean Mr. Trump has made a final decision on whether to strike, as military assets are often positioned to provide the president and commanders with options, even if those assets are not ultimately deployed.

Maggie Haberman , Eric Schmitt and David E. Sanger contributed reporting.

June 20, 2025, 7:45 p.m. ET

Elena Shao and Junho Lee

An Iranian strike in downtown Haifa damaged at least two places of worship.

An Iranian missile struck an abandoned building in the port city of Haifa, Israel’s third-largest city, early Friday morning. The blast damaged several surrounding buildings, including a mosque and a church.

Haifa, Israel

Abandoned building

hit by missile

Government complex

that includes the

Ministry of Interior

Mosque

Church

N

Abandoned building

hit by missile

Government complex

that includes the

Ministry of Interior

Mosque

Church

N

Mosque

Government complex

Source: Aerial image by Airbus via Google Earth taken on Dec 2 2024. Photos by Rami Shlush/Reuters, left, and Florion Goga/Reuters, right.

Clerics were present at the mosque at the time of the strike, the Israeli Interior Ministry said in a statement.

The Church of Our Lady and the House of Grace, a halfway house associated with the church, were also damaged by an explosive blast, according to Jamal Shehade, the director of the halfway house. Mr. Shehade described the damages to the church building, which was erected in 1862, as not being severe, but said the colored glass windows had been shattered.

A nearby government building that houses the Ministry of Interior was also partially damaged, according to photos and videos taken after the blast.

Iran had previously struck Israel’s largest oil refinery, in nearby Haifa Bay.

Adam Rasgon and Johnatan Reiss contributed reporting.

June 20, 2025, 5:23 p.m. ET

Ashley CaiAlbert Sun and Lazaro Gamio

How far could Iranian missiles go?

Estimated range of Iran’s ballistic missiles

U.S. bases or sites with recent U.S. military presence

Iran

Israel

Iraq

Syria

Saudi Arabia

Kuw.

U.A.E.

Qatar

Bahrain

Oman

Egypt

Jordan

Djibouti

Turkey

Short range

Up to 435 miles

Medium range

Up to 1,240 miles

Source: CSIS Missile Defense Project

Note: Minimum range estimates for Iran’s missiles are shown.

Thousands of U.S. troops in the Middle East are stationed at bases within range of an Iranian missile strike. Iranian officials have acknowledged that the country would attack U.S. bases in the Middle East if the United States joined Israel’s war.

Many of Iran’s missile launchers are mobile, allowing them to be positioned in more advantageous locations and maximizing the country’s firing range.

The complete picture of Iran’s missile stockpile is murky, but a 2022 estimate stated that the country had more than 3,000 missiles of varying ranges. At the start of the war, some Israeli officials estimated that there were around 2,000 missiles in Iranian stockpiles.

Some of these missiles have a range of up to 2,000 kilometers, which could easily cover the 1,400 kilometers separating Iran and Israel. Many U.S. bases are within striking distance of missiles with shorter ranges.

Israeli officials estimate that between a third to half of Iran’s stockpile is gone, used up by missile launches or having been destroyed in Israeli strikes. By Wednesday morning, Iran had fired roughly 400 missiles. Iran has begun to fire far fewer missiles in its barrages, possibly indicating that it is rationing its munitions.

June 19, 2025, 3:23 p.m. ET

Bora Erden

Israel struck an inactive Iranian nuclear site.

A satellite image shows damage at the Arak nuclear site. The main react is hit, along with three other structures.

Distillation

towers hit

Building

destroyed

Nuclear

reactor struck

Distillation

towers hit

Building

destroyed

Nuclear

reactor struck

Source: Satellite imagery from Maxar Technologies

Israel said it targeted Iran’s Arak heavy water reactor site on Thursday morning “to prevent the reactor from being restored and used for nuclear weapons development.”

The Israeli military posted a video of the strike on social media, showing several explosions.

The site had been one of Iran’s key nuclear facilities, once thought to produce weapons-grade plutonium. But as part of the Obama administration’s 2015 nuclear deal with Iran, the site was retired and concrete poured into the core of the reactor.

Before the strike, the Israel Defense Forces issued an evacuation order on X for an area around the site.

Source: Israeli military

By Elena Shao

Iranian state media reported that there had been no serious damage, no casualties and no radiation leak as a result of the strike at Arak.

The International Atomic Energy Agency, the United Nations nuclear watchdog, confirmed that there were no radiological effects from the attack.

June 18, 2025, 11:15 p.m. ET

Ani Matevosian and Elena Shao

Iranians mostly lost internet access on the sixth day of Israeli strikes.

Note: Local time is shown.

Source: Internet Outage Detection and Analysis

A near-total internet blackout that began in Iran on Wednesday evening essentially prevented Iranians from communicating with the outside world, as Israeli military strikes hit the country for a sixth day.

Connectivity to the global internet dropped to about 3 percent in Iran at around 5:30 p.m. local time, according to data from the Internet Outage Detection and Analysis project at the Georgia Institute of Technology that monitors internet outages worldwide. There was a short-lived recovery a few hours later, followed by a quick return to a near-complete shutdown, the data showed.

The shutdown appeared to be the result of an internal decision rather than a consequence of an Israeli strike. Earlier in the week, the Tasnim news agency, affiliated with Iran’s Revolutionary Guards, had said that Iran would disconnect from the global internet on Tuesday night, and that Iranians could still use a national internet service that allows people to message on government-approved platforms.

Experts and citizens say that the government is likely throttling internet access to prevent people from sharing information about where Israel has struck and for fear of Israeli cyberattacks.

Residents in Iran have reported severe disruptions to internet and phone services since the war began. Internet connectivity deteriorated slightly, by about ten percent, in the first five days following Israel’s initial strikes on Iran last Friday.

Iranian officials told The New York Times on Tuesday that services had been restricted in an effort to combat Israeli operatives that they said were still carrying out covert operations. The claim could not be independently verified.

Since the blackout started, reaching people by phone inside the country has become extremely difficult and many news media sites have stopped updating. The disruptions may be affecting residents’ ability to see evacuation notices, including ones that the Israeli military has posted on social media ahead of strikes inside Iran.

Iran’s state broadcaster on Tuesday urged people to delete WhatsApp from their phones, claiming that the messaging app was collecting user information to aid Israel. WhatsApp said the allegations were false.

June 18, 2025, 6:12 p.m. ET

Daniel Wood and Elena Shao

Tehran is about as densely populated as New York City.

Israel has expanded its attacks on Iran’s densely populated capital city, in recent days warning many of Tehran’s residents to evacuate ahead of strikes.

Population density in Tehran

Higher

Population density: Lower

Evacuation areas

named by Israel

Tajrish

Qods

Tehran

Mehrabad

International

Airport

Map

extent

Iran

5mi

Population density: Lower

Higher

Evacuation areas

named by Israel

Tajrish

Tehran

Mehrabad

International

Airport

Map

extent

Iran

Eslamshahr

5mi

Source: 2025 Global Human Settlement Layer provided by the European Space Agency.

By The New York Times

With around 10 million people within its nearly 300 square miles, according to the C.I.A. World Factbook, Tehran is comparable in density to New York City. About one in 10 Iranians lives in Tehran proper, and millions more live in its greater metropolitan area.

Photos and videos taken in the capital in recent days show long lines of cars at gas stations and congested traffic on the roads as people try to flee. The sense of fear escalated on Monday evening after the Israeli military issued an evacuation order for a zone in District 3, a densely populated upscale residential center of several hundred thousand people. Hours later, President Trump also warned in a Truth Social post that the entire population of Tehran should “immediately evacuate.”

And on Tuesday, the fifth day of back-and-forth attacks, the Israeli military issued another evacuation warning for an area that covered part of District 18. That district is just south of the Mehrabad International Airport, and is one of the poorest neighborhoods in Tehran.

The Israeli military said that it had targeted military and critical energy infrastructure, particularly the facilities and resources Iran needs to build nuclear weapons. The New York Times verified strikes in both dense residential areas, including the cities of Tabriz and Mashhad, and less populated areas, like Natanz, which is home to Iran’s largest uranium enrichment center.

June 18, 2025, 2:42 p.m. ET

Lara Jakes

There are about 40,000 U.S. troops in the Middle East.

Where U.S. Forces Are Deployed in the Middle East

About 40,000 U.S. troops are currently stationed across the Middle East.

Long-term U.S. military bases

Other military sites with recent U.S. military presence

Kuwait Five installations are located here. They can hold more than 13,500 troops.

Al Udeid Air Base U.S. Central Command regional headquarters can accommodate more than 10,000 troops.

Al Asad Air Base Many of the approximately 2,500 U.S. troops in Iraq are located at this Iraqi base.

Al Asad Air Base Many of the approximately 2,500 U.S. troops in Iraq are located at this Iraqi base.

Iran

Iran

Israel

Iraq

Syria

Saudi Arabia

Afghanistan

U.A.E.

Turkmenistan

Qat.

Bahrain

Oman

Yemen

Egypt

Egypt

Sudan

Jordan

Djibouti

Eritrea

Turkey

Tehran

Tel Aviv

Source: Congressional Research Service

Note: Troop numbers and locations are approximate and fluctuate.

By Daniel Wood and Lazaro Gamio

Thousands of American troops could be in Iran’s direct line of fire if President Trump joins Israel in attacking Tehran’s nuclear program and military, as he said on Wednesday he might or might not do. Experts expect that if Mr. Trump orders the American military to directly participate in Israel’s bombing campaign, Iran will quickly retaliate against U.S. troops stationed across the Middle East.

More than 40,000 active-duty U.S. troops and civilians are working for the Pentagon in the Middle East, and billions of dollars in weapons and military equipment are stored there. See the locations of major long-term bases and other sites above, and read more about the U.S. troop presence in the region at the link below.

June 18, 2025, 10:26 a.m. ET

Karen Yourish

See where Israeli strikes have damaged Iranian nuclear and military facilities so far.

Missile facilities

Nuclear facilities

Energy facilities

TURKMENISTAN

Caspian

Sea

Tabriz

Mashhad

Tehran

Most of the attacks so far have occurred in the western part of the country, where the largest number of facilities and cities are located.

Kermanshah

Natanz

AFGHANISTAN

IRAQ

Isfahan

IRAN

Kerman

Shiraz

KUWAIT

Bandar Abbas

SAUDI ARABIA

Persian

Gulf

QATAR

100 miles

U.A.E

TURKMENISTAN

Caspian

Sea

Tabriz

Mashhad

Tehran

Most of the attacks so far have occurred in the western part of the country, where the largest number of facilities and cities are located.

Kermanshah

Natanz

IRAQ

Isfahan

IRAN

AFG.

Kerman

Shiraz

KUWAIT

Bandar Abbas

SAUDI ARABIA

Persian

Gulf

QATAR

200 miles

U.A.E

TURKMENISTAN

Caspian

Sea

Tabriz

Tehran

Mashhad

IRAN

Kermanshah

Natanz

AFG.

IRAQ

Isfahan

Kerman

Shiraz

KUW.

Bandar Abbas

SAUDI

ARABIA

Persian

Gulf

250 miles

U.A.E

Most of the attacks so far have occurred in the western part of the country, where the largest number of facilities and cities are located.

Sources: Nuclear Threat Initiative, International Atomic Energy Agency, Global Oil and Gas Features Database, New York Times analysis of satellite imagery from Airbus, Maxar Technologies and Planet Labs, local news reports, and verified social photos and videos

The International Atomic Energy Agency said Wednesday that Israel struck two centrifuge production facilities in Iran, the latest hit to the country’s nuclear and missile infrastructure amid ongoing strikes that began last Friday.

Earlier attacks severely damaged Iran’s largest uranium enrichment center at Natanz. On Tuesday, the I.A.E.A. — the nuclear watchdog of the United Nations — confirmed “direct impacts” on the site’s underground enrichment halls.

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.

See What Strategic Infrastructure Israel Has Damaged in Iran

Israel has attacked nuclear, military and energy facilities in Iran. Here is a look at the destruction so far.

June 17, 2025, 12:45 p.m. ET

Lazaro Gamio and Karen Yourish

There are more than 40 nuclear and missile facilities throughout Iran.

Nuclear and missile facilities in Iran

TURKMEnistan

Caspian

Sea

Tabriz

Tehran

Iran

AfgHAN.

IrAQ

KUWAIT

Pak.

Bandar

Abbas

Persian

Gulf

Strait of

Hormuz

SAUDI

ARABIA

QATAR

Gulf of Oman

U.A.E.

250 miles

OMAN

TURKEY

TURKMEnistan

Caspian

Sea

Tabriz

Tehran

Afghanistan

Iran

IrAQ

Isfahan

KUWAIT

Pakistan

Bandar

Abbas

Persian

Gulf

Strait of

Hormuz

QATAR

Gulf of Oman

SAUDI

ARABIA

U.A.E.

250 miles

OMAN

Source: Nuclear Threat Initiative

The New York Times

Iranian officials have long asserted that their country’s nuclear program is intended solely for peaceful purposes, such as energy production and scientific research. But revelations in the early 2000s about undisclosed nuclear facilities, and work done up until 2003 on the design and delivery of nuclear weapons, led many nations to conclude that the country was walking to the threshold of becoming a nuclear weapons state.

Iran operates more than 30 facilities around the country that carry out different steps of the nuclear fuel cycle, including uranium enrichment, according to the Nuclear Threat Initiative. Tehran insists that its enrichment program is meant only to produce fuel for nuclear reactors.

Uranium enriched at low levels can be used as fuel for civilian purposes. Highly enriched uranium is used to make nuclear bombs, and Iran’s enrichment facilities (at Natanz and Fordo) contain advanced centrifuges capable of enriching uranium to high levels.

More than a dozen other facilities produce, test or house missiles, or otherwise support Iran’s missile program.

In 2015, President Barack Obama negotiated an agreement to limit Iran’s nuclear ability and to require monitoring and reporting requirements in return for lifting international oil and financial sanctions.

President Trump withdrew from the deal in 2018, saying it was not tough enough.

Late last month, the United States presented its first formal proposal to Tehran for elements of a new nuclear deal. The U.S. offer came hours after United Nations inspectors reported a major surge over the previous three months in the size of Iran’s stockpile of near-bomb-grade uranium. It proposed permitting Iran to continue to enrich uranium at low levels until an international consortium began manufacturing fuel for customers around the Middle East. President Trump said Iran appeared to have rejected the plan to ultimately stop it from enriching uranium on Iranian soil.

David E. Sanger contributed reporting.

June 17, 2025, 12:45 p.m. ET

Elena Shao

Here’s a look at the first four days of attacks between Israel and Iran.

Image

Credit...Arash Khamooshi for The New York Times

After Israel launched a surprise assault on Iran on Friday, confrontation between the two countries has escalated over four days, with neither side showing signs of heeding international calls for restraint. Here is a recounting, with maps, videos and photos, of the major developments in the first few days of the conflict.

Friday, June 13

In the early hours of Friday, Israel launched several waves of strikes at Iran, attacking military targets including nuclear sites and top commanders. The strikes prompted a retaliatory barrage of missiles from Iran, which struck at least seven sites around Tel Aviv.

Iran reported on Friday that 78 people had been killed and hundreds injured. Among the dead were two high-ranking military officers, Maj. Gen. Mohammad Bagheri and Gen. Hossein Salam, and senior nuclear scientists.

Evidence of strikes in Iran on Friday

The New York Times

Israel attacked Iran’s premier nuclear enrichment site at Natanz, about 140 miles south of Tehran, destroying the site’s aboveground plant and main electricity infrastructure.

Area damaged

in later strike

Damaged and

destroyed

buildings

Destroyed by Israel

in 2020

N

Area damaged

in later strike

Damaged and

destroyed

buildings

Destroyed by Israel

in 2020

N

Synthetic aperture radar image from Umbra Lab

By Bora Erden and Christoph Koettl

In the early afternoon, Israel carried out a strike on a military airport in the northwest Iranian city of Tabriz. A witness video verified by The New York Times shows large plumes of black smoke rising into the sky from the airport.

Video

CreditCredit...Verified social media, via Reuters

A section of a multistory residential building near Nobonyad Square, in northeastern Tehran, collapsed after it was struck, according to videos of the immediate aftermath that were verified by The Times.

Iran’s retaliatory strikes hit the Kirya area in central Tel Aviv, which is home to a number of government and military facilities, including the headquarters of the Israel Defense Forces. Several buildings in the area were damaged.

Evidence of damage in central Tel Aviv

170 ft.

Israel Defense Forces

headquarters

Israeli military

compound

The windows of a building

inside the Kirya government

complex were shattered.

Da Vinci Towers

apartment complex

170 ft.

Israel Defense Forces

headquarters

Israeli military

compound

The windows of a building

inside the Kirya government

complex were shattered.

Eliezer Kaplan St.

Da Vinci Towers

apartment

complex

Sources: Aerial image by Airbus via Google Earth; Photos by AFP via Getty images (left) and the Associated Press (right)

By Samuel Granados

Saturday, June 14

Overnight, the Israeli military struck sections of Mehrabad International Airport in Tehran, and videos verified by The Times show thick black smoke billowing from the airport’s military hangars.

Video

CreditCredit...The New York Times

An Iranian missile landed in a residential area of Rishon LeZion, south of Tel Aviv. A video taken later shows extensive damage to homes there.

On Saturday evening, Israel intensified its attack on critical energy infrastructure in Iran, widening its military campaign. Drones targeted a section of the South Pars Gas Field in Bushehr Province, one of the world’s largest gas fields and a critical part of Iran’s energy production.

Later, Israel took out two major energy facilities in Tehran: the Shahran fuel and gasoline depot and Shahr Rey, one of the country’s largest oil refineries. A video verified by The Times shows the Shahran depot ablaze.

Video

CreditCredit...WANA, via Reuters

Sunday, June 15

Iranian missile barrages on Israel killed at least eight people overnight, including four in the city of Bat Yam, south of Tel Aviv, where a blast heavily damaged a multistory apartment complex.

Israel bombarded Tehran in a rare daytime assault on Sunday afternoon.

Image

Smoke from explosions after Israel’s attacks on Tehran on Sunday. Credit...Arash Khamooshi for The New York Times

Israel said it had also struck an airport in Mashhad.

Iran’s health ministry reported that at least 224 people had been killed and more than 1,400 injured. Israel’s death toll was at least 24, with roughly 600 injured, according to the Israeli government.

Monday, June 16

Early Monday morning, the Israeli military warned residents in several areas of an imminent Iranian attack and urged them to remain near shelters and safe rooms. Iran struck a residential block in Petach Tikva, in central Israel, killing at least four people, officials said.

Iranian missiles also hit Israel’s largest oil refinery, located in Haifa Bay in northern Israel, according to footage verified by The Times.

The Israeli military claimed it had attacked the elite Quds Force’s command center in Tehran, though the claims could not be verified independently.

The Israeli military later published an announcement on social media telling people in a densely populated residential district of northeastern Tehran to evacuate, saying it planned to target military infrastructure there.

By Daniel Wood

Hours later, Israel struck the offices of Iran’s state broadcaster, the Islamic Republic of Iran Broadcasting, which is in the same district. Video feeds, verified by The Times, show the headquarters of the broadcaster burning and thick pillars of smoke rising from the building.

Video

CreditCredit...Iranian State TV, via Associated Press

Mapping the First Four Days of Attacks in the Israel-Iran Conflict

Israel launched a series of strikes against Iran, targeting the country’s nuclear program and other military infrastructure. Iran launched its own strikes in retaliation.

June 16, 2025, 6:47 p.m. ET

Helene CooperEric Schmitt and Samuel Granados

News Analysis

Iran’s best-protected nuclear site is so deep underground, only a huge U.S. bomb could reach it.

Fordo nuclear site

Deep inside a mountain,

Fordo is said to contain close

to 3,000 sophisticated centrifuges

in two enrichment halls.

IRAN

Support

building

Tunnel

entrances

Security perimeter

Fordo nuclear site

IRAN

Deep inside a mountain,

Fordo is said to contain close

to 3,000 sophisticated centrifuges

in two enrichment halls.

Support

building

Tunnel

entrances

Security perimeter

Fordo nuclear site

Deep inside a mountain,

Fordo is said to contain close

to 3,000 sophisticated centrifuges

in two enrichment halls.

IRAN

Support

building

Tunnel

entrances

Security perimeter

Sources: Nuclear Threat Initiative; Google Earth (terrain)

Iran’s most heavily fortified nuclear site, Fordo, was built deep inside a mountain to protect it from an attack. Only the U.S. military has the 30,000-pound bomb capable of even reaching it.

The bomb is commonly known as a “bunker buster” because it is designed to destroy deep underground bunkers, or well-buried weapons in highly protected facilities. It is believed to be the only air-delivered weapon that would have a chance of destroying the site.

The bomb has a much thicker steel case and contains a smaller amount of explosives than similarly sized general-purpose bombs. The heavy casings allow the munition to stay intact as it punches through soil, rock or concrete before detonating.

Its size — 20 feet long and 30,000 pounds — means that only the American B-2 stealth bomber can carry it.

Conventional wisdom has been that Israel can’t destroy Fordo on its own. The United States has blocked Israel from getting the bunker buster, and while Israel has fighter jets, it has not developed heavy bombers capable of carrying the weapon.

But Israel can come close by hitting more accessible power generation and transmission plants that help run the facility, which contains Iran’s most advanced centrifuges, military officials said.

In conjunction with Israel’s aerial bombardment of Iran, going after the Fordo-adjacent plants could significantly slow down the ability of Iran’s most protected nuclear facility to keep enriching uranium.

The Israel Defense Forces and covert operatives could also look for other ways to disable the site, including destroying the entrance to it.

Attacking Fordo is central to any effort to destroy Iran’s ability to make nuclear weapons.In March 2023, the International Atomic Energy Agency reported that it had discovered uranium that had been enriched to 83.7 percent purity in Fordo — close to the enrichment level, 90 percent, necessary for nuclear weapons.

Iran, which is a signatory to the Nuclear Nonproliferation Treaty, has maintained that its nuclear program is for peaceful purposes.

The U.S. Air Force is moving refueling tankers, aircraft and additional warplanesto support any additional American operations in the Middle East, U.S. officials said.

But President Trump has not, at the moment, moved to reverse years of American policy on providing Israel with the bunker buster bombs.

“We’ve had a policy for a long time of not providing those to the Israelis because we didn’t want them to use them,” said Gen. Joseph Votel, who was commander of U.S. Central Command during Mr. Trump’s first term. Instead, the United States viewed its bunker buster bomb largely as a deterrent, a national security asset possessed only by America, but not one that, if made available, might encourage Israel to start a war with Iran.

Iran built the centrifuge facility at Fordo knowing that it needed to bury it deep to prevent it from being attacked. In 1981, using F-15 and F-16 fighter jets, Israel bombed a nuclear facility near Baghdad as part of its effort to stop Iraq from acquiring nuclear weapons. That facility was above ground.

“The Iranians fully understood that the Israelis would try to get inside their programs and they built Fordo inside of a mountain a long time ago to take care of the post-Iraq problem” presented by the 1981 strike, said Vali Nasr, an Iran expert who is a professor at Johns Hopkins University.

Over the years, the Israelis have cooked up a variety of plans to attack Fordo in the absence of U.S.-supplied bunker busters. Under one of those plans, which they presented to senior officials in the Obama administration, Israeli helicopters loaded with commandos would fly to the site. The commandos would then fight their way inside the facility, rig it with explosives and blow it up, former U.S. officials said.

Israel successfully mounted a similar operation in Syria last year when it destroyed a Hezbollah missile production facility.

But Fordo would be a much more dangerous endeavor, military officials said.

American officials say now that Israel has gained air supremacy over much of Iran, Israeli attack planes could circle over Fordo and render it inoperable, at least temporarily, but not destroy it.

“The Israelis have sprung a lot of clandestine operations lately, but the physics of the problem remain the same,” said Gen. Kenneth F. McKenzie Jr., who was in charge of the Iran war plans when he ran the Pentagon’s Central Command after General Votel. “It remains a very difficult target.”

David A. Deptula, a retired three-star Air Force general who planned the American air campaigns in Afghanistan in 2001 and in the 1991 Persian Gulf War, agreed that Israel has options that would not require American help.

For example, Israeli special forces “could insert/apply or otherwise use a variety of means to disable the facility,” he said.

Yechiel Leiter, Israel’s ambassador to the United States, hinted at those options on Sunday on ABC News’s “This Week.”

“We have a number of contingencies, which will enable us to deal with Fordo,” he said. “Not everything is a matter of taking to the skies and bombing from afar.”

Even if Mr. Trump were to authorize American B-2 stealth bombers to drop the 30,000-pound bombs, General McKenzie said, there would be several technical, highly classified challenges in coordinating such a strike with Israel.

A decision to use the American bunker busters would also have huge international consequences, General Votel said. For one, there could be nuclear contamination from such a bombardment that could endanger civilians.

“I think there would also certainly be fallout internationally over the idea that the United States joined Israel in what would be viewed as an illegal attack on the sovereignty of Iran,” General Votel added.

And Iran could widen its retaliation to U.S. troops and other American targets in the region and beyond, military analysts say. The United States would be back on war footing in the region.

Mr. Trump has made clear that he has little interest in more military misadventures in the region, and he is seeking not to alienate a noninterventionist wing of supporters firmly opposed to more U.S. involvement in a Middle East war.

Adam Entous contributed reporting.

……