Original subtitles

>> Our objective is to defend the American people by

eliminating imminent threats from the Iranian regime.

>> SEBASTIAN WALKER: In the weeks since the U.S.

and Israel attacked Iran, President Trump has repeatedly

justified the strikes by claiming Iran was an imminent

nuclear threat.

>> If we didn't do what we're doing right now, you would have

had a nuclear war, and they would have taken out many

countries, because you know what, they're sick people.

If we didn't knock the hell out of them,

they would have had a nuclear weapon

within two to four weeks.

They would use it within- the only question is within one hour

if they did it, or one day.

>> WALKER: In the name of tackling that threat, the U.S.

and Israel have launched thousands of strikes on Iran's

nuclear sites, military and civilan infrastructure, and

leadership, for the second time in less than a year.

>> Israel has confirmed that the Supreme Leader of Iran,

Ayatollah Khamanei, has been killed.

>> WALKER: Iran has responded by launching attacks on Israel and

U.S.-allied states in the Gulf.

♪ ♪

>> WALKER: Is it possible we can go to Keraj?

It's where they say they were manufacturing the centrifuges.

>> WALKER: For months before the war, we'd been investigating the

status of Iran's nuclear program.

We visited sites hit in the first round of the U.S. and

Israeli strikes last year, which President Trump said

‘obliterated' the regime's nuclear facilities, and sat down

with one of Iran's most powerful officials, Ali Larijani, in what

would be one of his last interviews before he was killed

in an Israeli airstrike.

What's your message to the Trump administration

if there are more attacks?

>> (speaking Farsi)

(explosion booms)

>> WALKER: Since the current war broke out, we've been talking to

experts and officials...

President Trump has said that one of the

reasons for these attacks is that Iran

was on the verge of a bomb.

Is that the case?

And analyzing satellite imagery with our partners at the

Washington Post, Bellingcat and Evident Media...

>> There have not been any major developments that have pointed

towards any strong signatures of a return to nuclear capacity.

>> WALKER: To try to understand the truth about what remains of

Iran's nuclear program, and what kind of threat it could pose.

>> In terms of the nuclear question, what we don't know is

what Iran will do next.

The Islamic Republic is built for survival.

It's been planning for a day like this since the early 2000s.

(traffic passing by)

♪ ♪

>> SEB WALKER: Last summer, in the aftermath

of the first wave of U.S. and Israeli attacks,

I was getting ready to head to Iran.

Given the challenges of reporting there,

we'd partnered with

"The Washington Post's" visual forensics team

to help guide us on the ground,

and were working with investigative journalists

from nonprofit outlets Bellingcat and Evident Media.

Israel had assassinated nuclear scientists,

and the U.S. had bombed major nuclear facilities.

Our team was poring over satellite imagery

to understand from afar the impacts of the strikes

and how much the nuclear program had been set back.

Nilo Tabrizy speaks Farsi, and had been

combing social platforms accessible in Iran

for images and video

of locations that were hit.

We've been told

we could get access to the site of an assassination and also

speak to family members of a... of a killed scientist.

>> That would be really helpful to us,

because we were only able to confirm

about five of these names with their locations.

I think we've gotten close to exhausting

what we can do from afar, and this is really where

the field reporting is going to come in handy.

>> WALKER: Eric Rich is the "Post's"

deputy investigations editor.

Good to see you. >> Good to see you.

>> WALKER: Thank you. >> Have a seat.

I mean, it would be great

if we could coordinate while you're there.

As you start to get a sense of, like,

which scientists' families you might be able

to talk to, let us know immediately,

and we can start to build sort of a dossier around that strike.

Also, if anybody is able to share photos

that they may have in their phones

from immediately after,

that would obviously be of even greater interest.

>> WALKER: So sending pictures back, sending videos back,

that's something that's, that's helpful for you guys.

>> That would be hugely helpful, and we can, in real time,

we can analyze them and try to, you know, understand

if we can draw some conclusions or inferences that might

shape questions, further questions that you can ask.

♪ ♪

>> WALKER: In May 2025,

the International Atomic Energy Agency had said

that Iran had increased its stockpile

of near-weapons-grade enriched uranium,

though hadn't found evidence

of a systematic nuclear weapons program.

But Israel believed Iran was just a short step away

from producing a nuclear bomb,

which they saw as an existential threat.

On June 12, they seized the moment.

>> We're hearing a statement

from Israeli prime minister Benjamin Netanyahu.

>> Moments ago, Israel launched

Operation Rising Lion to roll back the Iranian threat

to Israel's very survival.

(explosion echoes)

>> In and around the capital, Tehran,

Israeli targets seem to be expanding.

>> The Iranians acknowledging

that some of their senior military leaders

have been killed or wounded.

>> WALKER: The first wave of attacks hit nuclear facilities,

military targets, and apartment blocks in Tehran.

I've reported from Iran before, and foreign journalists

especially are always closely monitored.

This time, it was even more so.

The government was tightly controlling

where we went and who we could talk to.

(phone camera snaps)

But it was a chance to see

some of the damage up close.

Our government minders brought us

to one of the locations that was hit,

a building we were told was known as

the "Professors' Complex,"

since many academics lived there.

We were shown around by Iraj Rasooli,

a microbiologist, and his relative, Hanieh.

(debris clatters)

Whoa, it's still falling down.

>> Yeah.

Just be careful, huh? >> WALKER: Yeah.

>> Sixth floor was hit.

Where we are standing is third floor.

>> WALKER: Okay. >> Four, five,

and one above that, six.

From ninth floor to third floor, 100% destruction.

I was sleeping there.

That was my bedroom.

My elder daughter was sleeping here,

younger daughter was sleeping there.

So when I went to help her brother,

he was thrown from his bed, here he was sleeping, to that corner.

So when I went to help him, to lift him up,

so his entire skin came on my hand.

It was so bad, he was so badly burned.

>> WALKER: Rasooli said his son-in-law died.

So did his daughter and grandson.

Living three floors above them

was a physics professor named Mohammad Tehranchi.

He was seen by Israel as a key player

in Iran's pursuit of a nuclear weapon,

and was sanctioned by the U.S. in 2020.

Did you know the person that they were targeting?

>> Yeah, yeah.

>> WALKER: You, you knew him personally?

>> I knew him, yeah, I knew him.

Yeah. >> He knew, but he didn't know

that he is an important person for the government...

>> Yeah, I didn't... >> WALKER: You didn't know

that he was doing this, this role in the, in the program?

>> We didn't know... we knew that he was a physicist,

and he was chancellor of Islamic Azad University.

>> WALKER: Mm. >> We knew this much.

So what Israel knew more than us, that is up to them.

(chuckling): We don't know, we don't know.

(phone beeps softly)

>> WALKER: Hey so I just wanted to send a voice note.

(on phone): We're at a building in the north part of Tehran.

This is the site of one of the...

killings of one of the scientists.

Here on the floor below where his apartment was,

and I think there are six floors that are missing here.

So, the size of the munition that was used

was extensive.

(men talking in background, objects clattering)

(on phone): There were civilians killed alongside this scientist.

This is Dr. Mohammad Tehranchi.

He's a professor of physics at one of the universities,

and the residents here say that they didn't really have

any sense that he was associated with the nuclear program.

Another strike in Tehran,

less than two hours later, killed a scientist

named Fereydoon Abbasi, who used to head

the government agency that runs Iran's nuclear program.

He had been sanctioned by the U.S. and E.U.

and survived an assassination attempt in 2010

widely attributed to Israel.

As we traveled around Tehran, we saw posters of both men

celebrated as martyrs.

Both Abbasi and Tehranchi

were buried alongside top military commanders

also killed in the Israeli strikes.

Thousands attended the funerals.

(man singing in Farsi over loudspeakers)

>> WALKER: Our reporting was helping the "Post"

develop a picture of the importance of Tehranchi

and the other scientists killed.

>> So, he seems like a really critical character in this.

Do we have any sense of whether he and the others

were targeted for their general expertise

or, like, a specific project that they were working on

that was part of the alleged nuclear program?

>> I talked about this with a few different sources,

about how important are these guys,

and someone mentioned they went after older scientists.

None of these were younger people in the field.

And so this one expert said it's probably because

they want to try to destroy the brain trust,

like, the, you know, the people who were foundational in this.

But the other side of it is that for the past decade or so,

maybe even longer, there's been a big push in Iran, apparently,

to have people train and study up

in, in theoretical physics and nuclear work.

>> WALKER: We repeatedly asked our minders if we could speak

to relatives of the assassinated scientists,

who Israel claimed were leading Iran's nuclear program.

They finally agreed to introduce us

to Tehranchi's brother, Amir.

>> WALKER: So the U.S. says that he played a leading role

in efforts to develop a nuclear device

in the mid-2000s, up to 2003.

What's your response to that?

>> (speaking Farsi):

>> WALKER: So he was placed on the list of sanctions

by the U.S. government.

Were you surprised when this happened?

>> (speaking Farsi):

>> WALKER: For people outside of Iran who are questioning

how much these killings have set back

Iran's nuclear program,

how big a loss do you think it is to have his knowledge,

his expertise, taken out of the equation?

>> (breathes deeply)

(speaking Farsi):

(traffic humming in distance)

♪ ♪

>> WALKER: Hey, I just wanted to send you a quick note,

because we've just wrapped an interview

with Tehranchi's brother.

When we were done, he showed me photographs that he'd taken

that were on his computer.

There were what appeared to be fragments of the weapon,

pieces of metal, what looked like rotors,

and also, there was what appears to be a serial number.

>> S-M... >> WALKER: S-M-B...

>> BOTH: A-M-S-O-O-A-A.

>> WALKER: 2008.

He didn't want to give us the originals,

but we've filmed it on our camera,

and I've taken screenshots that I'm gonna send to you.

Working with open source investigators from Bellingcat,

the "Post" team started piecing together

how the strikes against the scientists were carried out.

>> So were there, were there markings

on the alleged fragments, or you, we couldn't make it out?

>> Yeah, there were some markings on there

that had a possible part number and a possible lot number.

You have S-M-B-A-M-S-0-0-4-A.

But with, a lot of these databases

are private from the arms company.

So, it's not something we can check using open sources,

especially if it's a weapon that hasn't been used before.

>> Trevor, is there anything at the strike site

that allows us to glean any insight into whether

this munition was fired from an aircraft or the ground?

>> So from the damage alone,

the experts we talked to, they weren't able to confirm that.

It's more likely that it was a longer-range munition,

like a ballistic missile or a cruise missile.

(traffic humming in distance)

>> WALKER: Over the course of several days,

we were taken around Tehran to various locations

where Israeli strikes had taken place.

We sent pin locations, photos,

and interviews with witnesses back to the team in the U.S.,

who combined it with satellite imagery

and geo-located video to start to piece together

a bigger picture of what happened.

♪ ♪

It was an assault at multiple sites across the city.

The strikes started in the early hours of the morning

and hit in quick succession.

Nine people Israel viewed as key to Iran's nuclear program--

scientists, engineers, physicists-- were killed.

We were able to confirm the locations

and tally civilian casualties

from the strikes on Abdolhamid Minouchehr

and Ahmadreza Zolfaghari,

both nuclear engineering professors,

killed just blocks from each other.

Further east, we confirmed the location

and casualties from the strike on Mansour Asgari,

a physics professor sanctioned by the U.S.

for alleged ties to nuclear weapons development.

And in Sa'adat Abad neighborhood--

where Tehranchi was killed--

witness accounts combined with images

of the direction of the blast and structural damage

indicated a weapon or weapons

with the force of a roughly 500-pound bomb.

Taken together, it reflected

an unprecedented campaign by Israel

in its scale, weaponry, and impact.

>> We've already done great things.

We've taken out their senior military leadership.

We've taken out their senior technologists

who are leading the race to build atomic weapons

that would threaten us, but not only us.

We've done all that and many other things,

but we are also aware of the fact that, uh,

there's more to be done.

(traffic passing by)

>> WALKER: "Washington Post" reporter Souad Mekhennet

spent time in Israel

interviewing senior intelligence and military sources

about the operation.

She was able to speak to a senior military official

who helped plan the assassinations,

which he said had been years in the making.

He let her record the meeting, but didn't want his face shown.

>> (on computer): We mapped out

a group of roughly 100 scientists,

and we made an extensive analysis.

And we ended up with a group of the most valuable targets

to be eliminated.

The second phase was developing the intelligence

and operation capability to precisely strike

and eliminate each one of these targets,

up to the level of an apartment in Tehran.

(on computer): We've made everything possible to minimize

the collateral damage that is expected,

and employed precise force only against targets

that we thought were critical to deny Iran's pursuit

of nuclear weapons.

Since knowledge is the core asset

of any weaponization program,

we assessed that the elimination

of all major nuclear scientists in Iran

is a major setback for the project.

♪ ♪

>> WALKER: We wanted to find out what Iranian officials

had to say about these scientists

Israel and the U.S. said were critical to the nuclear program.

The head of Iran's nuclear agency,

the AEOI, agreed to meet me.

♪ ♪

Security guards didn't allow us to film

until we were deep inside

his heavily guarded headquarters.

Mohammad Eslami oversees all the country's nuclear sites.

>> WALKER: How much has the killing of these scientists

set back the nuclear program?

>> (speaking Farsi):

>> WALKER: The U.S. says the goal of the nuclear program

is to produce a nuclear weapon.

What is your response?

>> (speaking Farsi):

♪ ♪

>> WALKER: We left Tehran and traveled south,

through the mountainous landscape

that's home to three nuclear sites that the U.S. and Israel

have said are the heart of Iran's secret weapons program,

where its stockpile of near weapons-grade uranium

was believed to be produced and stored.

Israel bombed the sites.

And on the tenth day of the 12-day campaign,

America joined the attack.

(explosions popping)

>> A short time ago, the U.S. military carried out

massive precision strikes

on the three key nuclear facilities:

Fordow, Natanz, and Isfahan.

>> In total, U.S. forces employed approximately

75 precision-guided weapons during this operation.

>> Iran's key nuclear enrichment facilities

have been completely and totally obliterated.

♪ ♪

>> WALKER: We arrived in Isfahan

12 weeks after U.S. cruise missiles

slammed into the nuclear facility

on its outskirts, where we were hoping to film.

The city looked different from trips we'd taken here before,

with fewer women wearing the hijab,

a sign of opposition that had been building for years

against theocratic rule.

(bells jangling)

As we waited for permission, our minders told us

we can ask people about the bombing.

But on that question,

no one wanted to speak.

Excuse me, do you guys speak English, by any chance?

>> Yes. >> WALKER: Can we interview you?

>> Um...

>> WALKER: On camera? Is it possible?

>> Um...

Oh, no. >> WALKER: Okay.

Can we talk to you on camera?

>> No problem, but...

>> WALKER: Uh-huh. >> What do you ask me?

>> WALKER: About the, the 12-Day War.

>> No. >> WALKER: Okay.

All right, thanks.

(people talking in background)

In the end, a message came from Tehran

that we're not going to be allowed to film

the damage at the center.

They claimed it wasn't safe.

This was as close as they would take us.

The bombed facility was just behind this ridge.

Do you think we could get a shot from that place?

>> It's a...

station for cable cars. >> WALKER: Mm.

For the nuclear center, could we drive close to it?

Even if we don't stop and get out?

>> Even from the car, you need permission.

>> WALKER: Even from the car? >> Yes.

♪ ♪

>> WALKER: But away from Isfahan,

my colleagues back in Washington

had been piecing together what happened there,

and at the other nuclear sites.

Isfahan is Iran's largest nuclear complex.

The U.S. says it launched more than two dozen

precision-guided tomahawks at the site in June 2025.

Satellite imagery obtained by

the "Post's" visual forensics team

showed damage to the main uranium conversion facility.

>> This piece of damage is from Israeli strikes previously,

and then this is when the U.S. hit the Isfahan center here,

and our sources told us that this damage means

that it was knocked almost completely out of operation.

>> WALKER: Isfahan is reported to have held

much of Iran's stockpile of highly enriched uranium--

and it's believed to be buried under the rubble there

to this day.

The U.S. said Natanz was struck

by two bunker-busting bombs

known as massive ordnance penetrators, or M.O.P.s.

Satellite imagery showed visible penetration points

that align with underground centrifuge buildings.

Israel had also struck the electrical infrastructure here,

crippling the site before the U.S. bombs did their damage.

>> And that electricity is so key,

because the centrifuges are spinning at such a high rate

that if the electricity is cut, the spinning will stop,

and that can compromise the structural integrity

of these very delicate machines,

such that they will spin out

and, and sort of destroy themselves.

>> WALKER: Fordow took the heaviest hit.

The U.S. focused the most powerful munitions

on what it considered Iran's most important enrichment site,

buried deep inside this mountain range.

The U.S. said B-2 bombers dropped 12 M.O.P.s,

most of them through two ventilation shafts.

Satellite imagery before and after the strike

showed two ventilation openings

that appeared to confirm this,

but not the extent of damage.

>> The M.O.P.s still could've undermined the centrifuges

even without penetrating the interior.

If they had penetrated the halls,

they would've-- it would've been catastrophic.

If it were to hit from above the facility,

but not inside the facility,

the force of that explosion would still sort of

move through the rock and rattle the facility

in a way that could cause

the function of the centrifuges to be undermined.

>> WALKER: Regardless of the damage,

the exact location and status of Iran's stockpile

of highly enriched uranium would remain

a key unresolved question about the country's nuclear potential.

In the meantime, our colleagues at the "Post"

had begun to detect new activity

at another underground facility that was not bombed in 2025.

>> (on phone): There's something I wanted to ask you,

as you're in a pretty sensitive reporting environment,

so I can't explicitly say the names,

but there is a site of interest that we have

that was not hit by U.S. strikes,

but it's an important site.

So I just wanted to flag-- there has been

some increased activity that we've seen on satellite imagery.

>> WALKER: The activity the "Post" had detected

was at a site built inside a mountain

called Kuh-e Kolang Gaz La, or Pickaxe Mountain.

On our journey back from Isfahan,

the road passed close

to Pickaxe Mountain.

We found an excuse to stop and take pictures.

The complex was somewhere in this range,

believed to be buried deeper

than any of the facilities that were bombed.

(message sent sound chimes)

>> Seb took some photos

from here of Pickaxe.

>> WALKER: Our photos added to a picture

the team was building on Pickaxe from satellite imagery.

>> You really get a sense of the topography there,

which you kind of lose in satellite.

>> Mm-hmm.

>> Part of the security infrastructure

that is expected at a secure site like this would be

building perimeter walls and security features

that help controls what comes in and what comes out.

Iran had said the purpose of Pickaxe Mountain

was to house a production plant for assembling centrifuges.

>> The ability for the regime

to reconstruct centrifuges

is going to be important

in their ability to bounce back,

which puts more eyes

on Pickaxe and if indeed there is centrifuge construction

taking place there, what that means is that

they would be able to come back relatively quickly.

>> WALKER: Analysts also suspect

that Pickaxe's dimensions and estimated depth

could be used for uranium enrichment,

or for storing near-weapons-grade uranium.

Using satellite imagery,

the "Post" was able to show the site was being fortified

and expanded.

>> Here, this summer on the right-hand side,

you can see the status of the, of the security wall underway.

You can see them making their way through the rock.

Now compare that

here on the left, now this fall, where you can see

that security perimeter becoming closer to completion.

>> I think what's so interesting about this site

is it gets at this question of what's next.

And we're seeing evidence, it sounds like,

of a continuation of the program in this... at this site.

>> WALKER: The satellite imagery showed that two tunnel entrances

had been covered with dirt and rock,

which experts say hardens them against possible airstrikes.

And piles of excavated material, or "spoil,"

next to the entrances,

had increased in size,

indicating continued tunneling activity.

Satellite imagery also showed the presence

of heavy equipment and construction vehicles.

(indistinct chatter) (car horn honks)

♪ ♪

>> (on phone): Hey, Seb, I just want

to touch base on Pickaxe with you.

The purpose of Pickaxe is unclear.

International inspectors have never gained

access to it.

So any information you could find out

would be really helpful.

>> WALKER: Hey, thanks for that.

We are now back in Tehran.

Hopefully, we're going to get to speak to a senior official.

I'll take it up with them, and I'll keep you posted.

Our trip near its end,

we finally heard that the senior official

we could meet was one of Iran's most powerful leaders.

Ali Larijani, who would be assassinated

by Israel just months later,

was in charge of both Iran's national security

and decisions around its nuclear policy.

He reported directly

to Ayatollah Khamenei.

Can you say definitively here, now, after the strikes,

that Iran has no intention of developing a nuclear weapon?

>> (speaking Farsi):

>> WALKER: And in the future, is, is that out of the question?

>> (speaking Farsi):

>> WALKER: With the sites that were hit by American strikes,

President Trump has said

that the enrichment facilities targeted

were completely and totally obliterated.

Is he right?

>> (speaking Farsi):

>> WALKER: There's a site south of Natanz where

international observers have seen

new reinforcements of the entrance;

there's been some activity noticed there.

It's known as Pickaxe Mountain.

Is there any new activity that these strikes have created?

Is there anything you can tell us about that site?

>> (speaking Farsi):

>> WALKER: What's your assessment of the extent

to which these sites have been damaged,

and how much this has set back Iran's nuclear program?

>> (speaking Farsi):

(man leading prayer)

>> WALKER: Before leaving Iran,

we'd visited Friday prayer at the Tehran University campus.

The imams here were handpicked by the Supreme Leader,

and they echoed his message: that the 2025 strikes

didn't devastate the country's nuclear program,

as the U.S. and Israel had stated.

>> (speaking Farsi):

>> WALKER: Instead, they said, the bombing had drawn

Iranians closer together

and hardened their resolve.

>> (speaking Farsi):

>> (chanting in Farsi):

>> WALKER: Despite the 12-Day war,

Iran and its leaders remained defiant,

and continued to shroud the nuclear program

in secrecy and mystery.

It was time to leave Iran,

and seek answers elsewhere.

In late 2025,

we traveled to Vienna, home to the IAEA,

the world's governing nuclear watchdog.

Rafael Grossi is the head of the agency.

His inspectors were on the ground

in Iran prior to the 2025 bombing,

but hadn't been allowed to return

to the sites hit by the U.S. and Israel.

You have the ability to assess damage

in a unique way that others don't.

W-what was your initial assessment after

the strikes on the, on the key facilities--

Natanz, Fordow, and Isfahan?

>> Obviously, without having physical access

to a place, any evaluation is partial.

It's not complete.

But the difference between

our assessment and the assessment of anybody else

is that we knew exactly what was inside.

>> WALKER: Can you give us an overall picture

of what that determination was?

>> The determination was, and still is,

that the damage was very substantial.

Very substantial.

>> WALKER: While President Trump had insisted Iran

was nearing a bomb,

Grossi said he hadn't seen

evidence of an active weapons program,

but he was concerned about

the amount of enriched uranium Iran had stockpiled.

>> All the access and inspections that

we were carrying out allowed us to determine

that there, there is no credible

information that would lead us

to believe that they were developing a nuclear weapon.

So this I think has to be said very clearly,

as well as the rest--

a number of, I mean,

a huge amount of near weapon grade enrichment,

and of course these technological capabilities

that were there, which were a source

of legitimate concern by the international community.

>> Do you think that there is a risk from these strikes

that it pushes Iran's nuclear program further underground?

>> If time passes and inspections do not resume,

well, then, there will be doubts.

And I mean, I'm not saying that there will be

an immediate consequence, but certainly the situation

will, will become a source of a greater concern

in terms of non-proliferation

or the potential activities leading to a nuclear weapon.

(crowd shouting)

>> WALKER: In the months that followed,

tensions continued to build.

After the Iranian regime violently cracked down

on a wave of anti-government protests,

killing thousands,

the U.S. began a huge military buildup in the region.

>> The U.S. military presence is growing in the Middle East

as tensions rise over Iran's nuclear capabilities.

>> The Pentagon says it's sending the Navy's largest

and most advanced aircraft carrier.

>> WALKER: Amid another round of negotiations,

President Trump began threatening Iran

again over its nuclear program.

>> My preference is to solve this problem through diplomacy.

But one thing is certain, I will never allow

the world's number one sponsor of terror,

which they are by far, to have a nuclear weapon.

Can't let that happen. (crowd applauds)

>> WALKER: Before I'd left Iran, I'd asked Ali Larijani

what the world could expect if there were more strikes.

What's your message to the Trump administration

if there are more attacks?

What would be the consequences of that?

>> (speaking Farsi):

(birds chirping)

♪ ♪

>> We begin this hour with fast-moving developments

out of the Middle East.

Israel says it has killed two senior

Iranian security officials in an overnight strike.

>> In the last hour, Ali Larijani,

a senior figure in the regime, he's now dead.

>> For decades, Larijani,

well, he was the calm and the pragmatic face,

if you'd like, of the Iranian establishment.

>> WALKER: A few months later,

Ali Larijani had been killed.

Along with Iran's supreme leader,

many of his senior officials,

and more than a thousand Iranian civilians.

In the middle of the nuclear negotiations, the U.S.

and Israel had once again launched

surprise attacks against Iran,

sparking weeks of escalating violence across the region.

>> Iran has been hitting back with attacks across the region.

>> A short time ago, the images coming in,

flames rising from the U.S. embassy in Baghdad.

>> Meanwhile, President Trump is calling on nations to help

secure the critical Strait of Hormuz.

>> I would just say that it's been

an extraordinarily successful campaign

over the last couple weeks.

>> WALKER: Senator!

I went to Washington as pressure

was building on the president and his allies

to provide evidence that Iran had posed an imminent threat.

>> Tonight, the administration's top counterterrorism official

resigning in protest over President Trump's war with Iran,

declaring Iran posed no imminent threat to our nation.

>> WALKER: In a series of hearings on Capitol Hill,

intelligence officials were grilled on the issue.

>> Was it the assessment of the intelligence community

that there was an imminent nuclear threat

posed by the Iranian regime?

>> The intelligence community assessed that Iran

maintained the intention to rebuild

and to continue to grow their nuclear enrichment capabilities.

>> Was it the assessment of the intelligence community

that there was a, quote, "imminent nuclear threat"

posed by the Iranian regime? Yes or no?

>> Senator, the only person who can determine what is

and is not an imminent threat is the president.

♪ ♪

>> WALKER: Nobody from the Trump administration

would agree to an interview.

But I was able to meet with the Israeli ambassador

to the United Nations,

who continued to insist

that Iran had been close to a nuclear weapon.

We believe that they were very close

to a point where they can actually assemble

the nuclear capabilities on the ballistic missiles.

Now, one can argue and say, "Well, it didn't happen."

But do you want to wait for that to happen?

Do you want for them to actually assemble it,

launch it, and then what?

>> WALKER: But with the nuclear sites,

the nuclear program,

there wasn't anything new

or urgent or imminent that you saw in that realm

in the lead-up to these. these recent...

>> No, I have said it very clearly.

They were moving forward.

And they had the uranium technology, ballistic missiles,

so the last thing they had to do is to assemble it together.

Now, I cannot go into details if they needed, like,

two weeks or two months to assemble,

but once we realized that they have the intention to do that,

we were very determined

to stop them. >> WALKER: How did you realize

that they had that intent? What changed?

>> Well, you know, we proved that we have good intelligence.

>> WALKER: Our reporting colleagues had

been analyzing the strikes

and the ongoing debate about the threat Iran posed.

>> (on computer): Hi, everyone. Good to see you all again.

Feels like there are a lot of big questions in front of us.

Who's going to control global oil?

What happens to Iran's

political leadership?

Critically, what's the status of the nuclear program

and the missile program?

I thought it would be useful

to go around the grid

and hear about everybody's reporting.

>> So this campaign began

unusually in daylight hours in Tehran and...

>> WALKER: Warren Strobel

is the "Post's" national intelligence reporter.

>> The campaign very quickly moved on to military targets,

primarily Iran's ballistic missiles,

I think there's something interesting going on here.

Both sides, both the U.S. and Israel,

are hitting military targets.

But Israel, and I've just seen a summary

of their campaign, they are deliberately taking

a lot of their attention, a lot of their firepower

at regime centers of oppression, I guess you call it.

They still hope that the people of Iran will

at some point rise up,

and they're trying to help that; they really want regime change.

Where it is a little less clear that the United States

is interested in regime change.

>> We've seen some strikes on

different civilian infrastructure, too.

So we are seeing,

you know, it's not just military,

civilian infrastructure, civilians are being impacted.

And even just in the first week of this operation,

the civilian death toll in Iran

surpassed that of the 12-Day war.

>> WALKER: Jarrett Ley had been examining satellite imagery

to assess whether Iran had been attempting to re-activate

its nuclear program in the run-up

to the most recent strikes.

>> At the nuclear sites,

what are we seeing?

>> Since we last reported on these sites last fall,

we've not seen any major attempts to reconstitute

or reconstruct these sites.

What we have seen is some preliminary measures at Isfahan,

leading up to the war,

which were understood by experts

as an ant... in anticipation of a forthcoming attack.

>> WALKER: The satellite imagery of Isfahan

shows that three tunnel entrances were back-filled

with dirt prior to the latest strikes,

as a potential defense against an attack.

But our team found no sign

of large-scale reconstruction

at any of the major nuclear sites,

including Isfahan, Fordow and Natanz.

>> In the run-up to this war, there was no

sort of new intelligence

indicating that Iran had made massive strides forward

in its nuclear program or ballistic missile program

that would have, perhaps, justified a conflict.

Obviously, they have an active nuclear program,

heavily damaged.

They have an active ballistic missile program,

which they're using in the war,

but there was no kind of sudden piece

of alarming intelligence.

>> WALKER: As for Iran's stockpile of enriched uranium,

our team have found no evidence

that the Iranians have tried to retrieve it

from the rubble of last year's strikes.

>> 900 pounds of uranium enriched

to 60% purity is a concern.

But for the Iranians to turn that into a bomb,

they would have to go get it.

They would have to move it securely

without being detected to a place where

they could further enrich it to 90%.

They would then have to take that highly pure,

gaseous uranium, form it into metal,

and put it atop a warhead with explosives

that cause a nuclear chain reaction.

So, um... of course, it's a concern,

but it seems a little bit hard for me to believe

that they could do all that while under intense bombardment

from the United States and Israel,

unless there's some aspect to the Iranian program

that we don't know about.

>> And Warren, to build off of that point,

as Nilo and I reported last summer,

the site at which they convert

highly enriched uranium from its gas form

to its metal form at Isfahan was struck and is destroyed.

And we've seen no evidence

that they've actually rebuilt that site.

>> WALKER: In the third week of the war,

the head of the IAEA, Rafael Grossi,

was in Washington for meetings with the Trump administration.

He agreed to sit down with me again.

President Trump has said that

one of the reasons for these attacks is that Iran

was on the verge of a bomb.

Is that the case?

>> Well, I would generally abstain

from commenting on comments,

from-- especially from presidents.

And what I can say is that the situation

in Iran was concerning.

>> WALKER: This time, Grossi was reluctant to challenge

the administration's justifications for war

but expressed frustration

that his inspectors were still blocked

from Iran's key nuclear sites.

>> We lost

the necessary continuity of knowledge

to be able to confirm

that everything in Iran was in peaceful use.

So, as to whether there was

a short distance or a long distance

to manufacturing nuclear weapons,

I would not get into that,

but it is clear that there were some elements of concern.

>> WALKER: Elements of concern, but...

...evidence of being close to a bomb.

Did you see anything-- >> We cannot have evidence

when we are not being given the access

to places and, and answers to questions

that we were having on a number of things.

>> WALKER: You said that much of Iran's

highly enriched uranium stockpile

was believed to be at Isfahan.

How confident are you in that assessment?

>> We believe that it's there.

We have been trying to follow,

observing the place, and so have others.

And the generalized point of view is that it's still there.

>> WALKER: Is there any possibility that Iran

could have retrieved these supplies?

Is that something that you would be able to observe or tell?

>> One cannot exclude completely without inspecting,

but as I said, we believe it's still there.

>> WALKER: Regardless of the nuclear question,

the U.S. and Israel have said that a major aim of the war

has also been to eliminate

Iran's conventional missile capabilities.

>> Our objectives,

given directly from our "America First" president,

remain exactly what they were on day one.

Destroy missiles, launchers,

and Iran's defense industrial base so they cannot rebuild,

destroy their navy, and Iran never gets a nuclear weapon.

>> WALKER: Back in September last year,

our minders in Iran had taken us

to the Islamic Revolutionary Guard Corps missile museum,

where Iran's latest military hardware was on display.

So are you familiar with all of these?

>> Yeah, these are a combination of space launch vehicles

and a couple of different launchers.

>> WALKER: Decker Eveleth is one of the leading researchers

on Iran's missile capabilities. >> Ah, here we go.

I knew it was somewhere along this valley.

>> WALKER: Like our team, he said he's seen no evidence

that Iran was within close reach of a nuclear weapon,

but he told me that based on his assessments,

it had been making concerted efforts

to rebuild its conventional missile stockpile

since the strikes in 2025.

>> So basically all of the missile production

facilities that were hit during the 12-Day War were rebuilt.

Whether or not they were rebuilt with actual

new production machines inside of those facilities?

Unknown, but they did do a lot of work

rebuilding those kinds of facilities,

because, I think at this point,

the missile program is just

the only thing they have left, really.

>> WALKER: But that in itself doesn't then pose

an imminent threat to the U.S. and its allies

in terms of Iran's weaponization of the nuclear program?

That's a different consideration.

>> Yes, different consideration.

They can do a lot of damage with those missiles, right?

But it's, it's a capability

they've had for a long time already.

And those missiles can't reach the homeland yet.

>> Israel and the United States continued to attack Iran today,

hitting the same kinds of targets

they've struck throughout this campaign.

>> President Trump threatened Iran,

saying if they don't reopen the strait within 48 hours,

the U.S. will start striking Iran's power plants.

>> WALKER: As the war has widened,

the U.S. and Israel have hit thousands of targets

across Iran.

>> They've successfully struck at least 22 missile bases.

They've basically taken out

the immune system to the ballistic missiles.

They can no longer produce new ones.

However, as we've seen out in the strait

and elsewhere, they still have munitions in storage.

>> Iran launched one of its most advanced

ballistic missiles to date against Israel.

>> Iran has heavily damaged many petroleum facilities

and other targets in the region.

>> The Strait of Hormuz is still being blocked by Iran

and that is sending global energy markets reeling.

>> They can maintain

a resilience within this war using those munitions

despite the United States'

and Israel's devastating hits on those facilities.

>> WALKER: Since the assassination of

Ayatollah Khamanei,

his son Mojtaba Khamanei has been appointed

as Iran's new supreme leader.

>> We don't know his leadership credentials.

He's never made a speech. He's never held public office.

We know that he's very close to the IRGC,

so a lot of people are, are saying

that it's really the IRGC running the show.

>> WALKER: As thousands more U.S. troops

arrive in the region, President Trump is

reported to be weighing a high-risk ground operation

to seize Iran's stockpile of highly enriched uranium.

At the same time, he has proposed a plan to end the war -

that, among other demands,

requires Iran to hand over the stockpile.

>> Talking to sources, the Islamic Republic is not

at a place where it wants

to have a negotiation and an off-ramp.

In Mojtaba's first statement, he talked about closing

the Strait of Hormuz. He talked about revenge.

>> Amid warnings, the war in the Middle East

is out of control,

Washington and Tehran don't appear to be any closer

to seeing eye-to-eye.

>> They are negotiating, by the way,

and they want to make a deal so badly,

but they're afraid to say it.

Because they figure they'll be killed by their own people.

(crowd chanting)

They're also afraid they'll be killed by us.

>> Iranian military is actually mocking the president's claims

of any talks,

saying the U.S. is negotiating with itself.

>> This regime is really built to withstand

this type of pressure.

Some sources I spoke to were very concerned

that if they survive this

attack on the future of the Islamic Republic,

that Iran could rush

to develop a nuclear weapon now as a form of deterrent.

The strikes in the summer devastated the three sites.

That we can say for sure.

But what we don't know is what Iran will do next.

Captioned by

Media Access Group at WGBH

access.wgbh.org

>> For more on this and other "FRONTLINE" programs,

visit our website at pbs.org/frontline.

♪ ♪

FRONTLINE's "Strike on Iran: The Nuclear Question"

is available on Amazon Prime Video.

♪ ♪