The summer skies over Tehran and Tel Aviv have been angry and loud. Missiles, warplanes, and drones flying back and forth for nearly a week now. Some shot down by air defenses, but others make contact.

Video from overnight showing massive explosions at the site of some of the strikes in northwest Iran.

Israel says it's going after Iran's nuclear program and key military sites. But make no mistake, civilians in Tehran are in the crosshairs.

We see this picture in our films too.

This man says he was thrown up against the ceiling when a blast hit nearby. He's only seen destruction like that in the movies. Schools have been opened as bomb shelters for those who are staying put.

Right now, I want to go out of Tehran for security reasons.

But people like this woman say they're packing up and leaving, if they can. Roads out of the city have been choked with traffic. And that's the thing. No matter how Iranians feel about the oppressive regime, or how Israelis feel about how their military conducts itself, these missiles still fly overhead, and everyone on the ground still has to deal with it. So what does that feel like, and where does this go? Today, CNN Chief International Correspondent Clarissa Ward takes us to Israel, and CNN Chief International Security Correspondant Nick Paton Walsh explains why Iran's nuclear program has both Israel and the U.S. Up in arms. From CNN, this is One Thing. I'm David Rind.

So Clarissa, where exactly in Israel are you right now?

I am currently in Tel Aviv.

You said something on TV the other day that is really stuck with me. You were out looking at damage from an Iranian missile strike and you said that Israelis are not used to seeing this kind of damage up close in Israel. I was like, yeah, I guess that's right. I mean, what kind of impact has that had on people there?

Absolutely. I think for people in Gaza or Lebanon or Syria, who have been on the receiving end of Israeli bombardment, these are scenes that are all too familiar. But for Israelis, it's been many decades since they've seen that kind of firepower, this kind of munitions, ballistic missiles, some of which, as we've seen firsthand, are taking out multiple houses, half a city block, more or less reduced to rubble and crumpled cars like coke cans and debris everywhere and civilian casualties. These are scenes that most Israelis have not seen in recent history, certainly. They are more used to smaller rockets, mortars. Suicide bombers, but these ballistic missiles are a whole new ballgame. And it's interesting to see because on the one hand, of course, that comes with a real anxiety and people here are fearful and the second the sirens go off, they run to shelters and they stay there and nobody really is taking any chances because they understand Just how lethal these weapons are. But on the other hand, when you talk to most people here, they are broadly supportive of Israel's strikes against Iran and this operation. And it has been framed to them very much as an existential issue. And so, they want to see the objectives of this operation be achieved.

Even if that means nightly waves of Iranian missiles coming over, people running into shelters and having to deal with that every night.

Hold on one second because we've just had an alert, which means it's not, can you hear?

Yeah, I hear that.

Dear guests – we expect an alarm in the next 15 to 30 minutes. Please prepare to stay near a protected space.

Can you hear me still? Yes. Hold on, I can't hear you, because what happens during these alerts is that your phone switches off whatever it's doing. So I was recording my voice doing this interview and it stops recording immediately. It disconnected my AirPods from the computer. Wow. Essentially, it's pretty sophisticated technology. The goal is to make sure that no matter what you're doing, if you're listening to music on your phone, if you are talking on the phone, that you have to. Basically listen to the alert.

Like, you can't opt out of listening to it.

Yeah. Okay. Now it's back. I have to start recording again. Hold on. Okay, so we'll try this again. I'm just warning you that as soon as the sirens go off, I will have to go and stand in the stairwell and we will almost certainly get cut off again.

Understood, safety first for sure. So that's not just a hotel thing, that's all over the place.

So the hotel announces it on the loudspeaker, but every single phone that is in Israel, you suddenly get a message basically telling you that it's time to go and find a shelter and you have about 15 minutes to do so. And then you hear the sirens. When you hear sirens, you have 90 seconds to get into the shelter. And then, you wait inside the shelter until you get the all clear.

I mean, yeah, so that's what you just described, is a very regular thing going on there for all Israelis. Undoubtedly stressful and disruptive, but you're saying that broadly folks there are supportive of the mission.

Obviously, there is a huge amount of ambiguity around the issue of just how close Iran was is to developing a nuclear weapon or whether that was even indeed their intention. But here in Israel, that ambiguity does not exist. Now you can hear the sirens. I'm just going to go, rather than going all the way to the shelter, I'm going to the stairwell.

And if you need to go there, obviously, feel free.

It should stop soon.

Okay. And tell me, did you know the Khatib family who were killed so tragically in the strike?

Usually I am in every event

'So we visited the town of Tamra, an Arab-Israeli town, which was struck on Sunday night into Monday morning, and four people were killed from one family, four women, the youngest just 13 years old, a mother, two of her daughters, and a relative, and the only member of the family of the children, I should say, who survived was this young girl who was sleeping in the room. That they used as a shelter or a safe room.

And you see the victims are innocent people, poor women. I think all women in the world have to move now and to say what did they do wrong? Those are sitting in peace in their houses.

'And what we found when we visited Tamra and talked to people there, including the mayor, is there's a feeling in many of these Arab Israeli towns who do not have as many shelters that there is basically neglect, that things that would be unacceptable and even illegal in a Jewish Israeli town are not prosecuted or held to the same standard with an Arab-Israeli town. Of course, many will say that it's up to the municipalities, the local municipalities, to oversee the construction of those shelters. But there was a feeling among people that we talked to there that their lives are not as valuable in the eyes of the Israeli government.

Well, so you're there in Israel, you've been giving us a little taste of what life is like there on a daily basis. But I'm wondering about folks in Iran, we've seen videos of these long lines of cars of people trying to get out of Tehran. Do we have a sense of what life is like there right now?

I think it's really hard to get a full picture of what life is like in Iran. I've been speaking to a number of journalists and civilians who are talking about being completely terrified in a state of panic, real confusion, lack of communication about what's happening, explosions going off throughout the night and the day. Chaos as people try to flee the capital. I've spoken to people who have moved out of Tehran to northern Iran. And many of the people who've reached out to me feel that they're kind of caught in the middle, in a sense, because they have no love for the regime in Iran at all. But at the same time, they are horrified by these strikes, these Israeli strikes. On their country, and they're petrified. And at the same time, it's important to be clear that there are a lot of people in Iran as well who do support the regime. It's not a monolith, there's not only one voice, and naturally the people who reach out to me are highly educated, English speaking, many have spent time in the West, and so they're reflecting a certain perspective or a certain viewpoint. The one thing that I would say is a through line that we see from different people there is real fear and real panic.

Yeah, I was going to say, when we hear talk of regime change from Benjamin Netanyahu, you know, like you say, it's not a monolith there. So there may be folks that certainly would support something like that down the line. But in the meantime, there are missiles raining down and buildings being blown.

I think you see this a lot in war zones, particularly when you're talking about ordinary people. Their primary concern is their security and the security of their loved ones and making sure that they have enough food and water and gas for their cars if they need to flee and somewhere that they can feel a little bit more secure if that's possible for them even. And so a lot of the politics and the geopolitics is of secondary importance, really. And I think it's easy to forget that sometimes. And we want to frame everything in a political way. And we forget that at the end of the day, a lot people are just human beings who are terrified.

Well, Clarissa live from the stairwell there in Tel Aviv. Thank you so much and stay safe. Thank you, David. Gotta take a quick break, but when we come back, the damage to Iran's nuclear program with CNN's Nick Paton Walsh.

So Nick, Israel's main stated reason for launching this operation against Iran was to cripple its nuclear program so that it could not obtain a nuclear weapon and threaten Israel's survival. So as we sit here on Tuesday morning, what exactly do we know about how much damage Israel has done to that nuclear program?

Yeah, it seems likely that a fair bit of damage has been done, but owing to the secretory of nature rule of this, it's impossible to give a definitive statement as to, yeah, okay, it's now impossible for them to build a nuclear weapon. Ultimately, I think it's the plant at Fordow buried deep into the mountains that appears to have not sustained damage yet, that is of the highest concern to Israeli assessments, and it's unclear if they have the ordinance to penetrate and damage that. So very much unclear. As to where Iran sits now.

Yeah, so can you explain this process to me a little bit because we're talking about the material needed to make a bomb. I hear the term enrichment being thrown around a lot in these conversations, you know, kind of a red line in the talks between the U.S. And Iran, but I realize a lot of people might tune out when they start hearing such sciency terms like that.

Yeah, sure. I mean, so it's reasonably simple if you think nuclear science is reasonably simple. For military use of uranium, you need to enrich it to about 90%. And at the moment, large amounts of Iran's enrichment occurs to about 60%. You can't just take the uranium you pull out of the ground and put in a nuclear weapon. It has to be massively refined to that kind of purity. Now, 60% only really has military uses, 90%. Absolutely only has military uses, most analysts say. And the jump between 60 and 90 is pretty small. So the alarm bells have slowly been ringing as Iran has got more and more 60% enriched uranium. The whole JCPOA, the Iran deal that Donald Trump pulled out of, that Barack Obama pulled together was designed to keep enrichment down to low levels that couldn't be used for weapons. Oh, so we don't...

Be used for like nuclear power, things like that.

And the big question people have always asked is why does Iran, one of the biggest producers of hydrocarbons in the region, need nuclear power? Well they've said it's their right and they've persisted with that and obviously there's been great suspicion as to whether or not this may indeed be about a nuclear weapon. The Supreme Leader has issued a fatwa in the past in which he said they don't want nuclear weapons, a religious decree of sorts. And so. I think the predominant suspicion has been that Iran is up to something less benign than just a civil nuclear program. But what appears to have occurred in the last days is Israel has stated clearly they believe they were about to make some kind of breakout move towards a bomb. No clear evidence about that and it's not something even their allies agree with.

Yeah. So CNN reported that, according to four people familiar with the US intelligence assessment, Iran was up to three years away from being able to produce and deliver one nuclear weapon to a target. Netanyahu said they were maybe months away from those capabilities.

Well, let's break down what the capabilities are. There's the enriched uranium you need to make a nuclear device. So that's the kind of material, the raw material you need for the bang. And I think most assessments have been for months, years now, that they could be 10 to 15 days away from making enough enriched 90% uranium from what they currently have to make bomb. Now, that's a very short timeframe, but ultimately it's just about the decision. You need to say you want to go and do that. The question that's been harder to answer is a very complex task of taking that material and turning it into a weapon and then putting that weapon onto some kind of delivery device like a missile and then delivering that to your target in question. That's a lot of complications there and I think a lot, frankly, in intelligence community is guesswork as to how glued up that process already is for Iran. Some assessments, like you said, say three years. Others more alarmist and so I think that's so much of the focus of the weeks and months ahead as we chew through what is happening or what has happened is exactly how accurate those readings were.

What's the US calculation in all this? Like, what do you think they're kind of weighing as they look at these volley of strikes back and forth every night?

I think their hand has been forced.

Iran cannot have a peanut butter weapon. It's very simple. You don't have to go too deep into it. They just can't have it.

I think it's reasonable to hear the public statements of President Donald Trump saying he didn't want to see this conflict happen, he wanted diplomacy, and take them as genuine. He's clearly afterwards tried to hint a bit more that he was on side of all of this.

What specifically is better than a ceasefire? What are you looking for here?

An end, a real end, not a cease fire.

So something that will be permanent?

Yeah, or giving up entirely.

I think he would potentially have preferred to have had diplomacy fix all of this, but when he sees success, the president of the United States kind of likes to be associated with it, and it's fairly hard, as far as what we know now, to not perceive the Israeli campaign as having been quite successful against Iran's military. Bear in mind, too, there are probably in the region of 200 or so dead Iranian civilians as a result of this according to Iranian health ministry figures. And I think the United States wants to be sure that this does not cause Iran to make a breakout to actually build the bomb that it so dreads. And so either has to give Israel adequate military support to finish the job, but the job may be very hard to finish, owing to the secrecy and protected nature of these key parts of the program, or has to use this moment for a coercive diplomacy in which it drags Iran to the table for a deal that's far inferior than the one it have got. Just a week ago. So I think the U.S. Doesn't want to get dragged into another war in the Middle East. The Iranians don't really have the resources to sustain this for much longer. The Israelis also too may be finding their inventory and their list of useful targets is diminishing. So I I think we're at a point maybe in the days ahead where we'll see this push for diplomacy or the aggression of Israel's strikers against infrastructure pick up as people try and bring an end to this. And I think really, the United States wants this to end, but end in a way that means Iran is unable to build a nuclear weapon.

One Thing is a production of CNN Audio. This episode was hosted and produced by me, David Rind, our senior producers, our Felicia Patinkin and Faiz Jamil, Matt Dempsey is our production manager, Dan Dzula is our technical director, and Steve Lickteig is the executive producer of CNN Audio. We get support from Alex Manasseri, Mark Duffy, Robert Mathers, John Dianora, Leni Steinhart, Jamus Andrest, Nicole Pesaru, and Lisa Namerow. Special thanks to Schams Elwazer, Andy Carey, Zeena Saifi, and Wendy Brundidge. We'll be back on Sunday. I'll talk to you then.