this is bbc news. we'll have the headlines for you at the top of the hour, which is straight after this programme. minus eight and a half minutes. nuclear weapons are one of the greatest threats to humanity. every year, there's a meeting to assess the risk of global catastrophe... ..and set the doomsday clock. the hands are currently at 90 seconds to midnight — the closest they've ever been. with unique access to the experts who set the clock...

this is a very dangerous time. leaders are not acting responsibly. ..i want to find out what's brought us from oppenheimer's invention to this point. "now i am become death, the destroyer of worlds." nuclear weapons, nuclear terrorism, nuclear proliferation. right now, it'sjust going in the wrong direction. translation: i'm ordering the strategic nuclear- forces on special alert. explosion. in britain, our own weapons are on high alert. there's always one out at 15 minutes�* notice to fire. somewhere out there? somewhere out there. and american nukes could soon be back on british soil. if we get trump in there next time, and he may press the button, because he's got a bigger button than putin, then we are a target.

on computer: this is one unseasonably bleak scene which has profoundly moved many people during 1982. well, here's the greenham peace camp. a0 years ago now. their peaceful protest against the siting of cruise missiles here is into its second winter... when i was a young reporter in the �*80s, then the nuclear threat was ever present. people talked about the threat of nuclear war between russia, then the soviet union, and america all the time. and then it went away and it really receded into the background, except i kept on... ..i kept on investigating. is the islamic republic actively seeking to get the means to make a nuclear bomb? it's often rogue nations, rogue actors, as they were called, trying to get weapons. north korea has tested

a nuclear bomb believed to be ten times more destructive than hiroshima. it's huge. so, what, the whole village comes in here? that's the idea? in the last few years, we've had a whole host of global uncertainties. and now it seems that the nuclear threat is really back on the agenda again. the story of the atomic threat begins almost 80 years ago, in 1916. archive: we have seen that before. l film showing the bursting of the first atom bomb, the experimental one in new mexico. it was dropped from a steel tower and filmed from about six miles away. afterwards, cameramen and reporters put on special canvas boots as a precaution against picking up dangerous particles left in the circle of devastation. and as for the steel tower from which the bomb had been dropped, this is all that was left of it. i've come to new mexico,

in america. it's all pretty barren and empty out here. i can see why it would be an area to test weapons. the small town of los alamos was the birthplace of the atomic bomb. it feels so peaceful here. it's extraordinary to think that this is where it all started. this is where the first atomic bomb was built and developed by robert oppenheimer and his team, the so—called father of the atomic bomb. we had a moment where it looked like the chain reaction from an atomic device might never stop. are we saying there's a... ..chance that when we push that button, we destroy the world? chances are near zero. near zero? what do you want from theory alone? zero would be nice. the recent hollywood blockbuster oppenheimer told the story of the manhattan project and the development

of the first atomic bomb. this modest little log cabin right on the end is the house where oppenheimer himself lived during those months he was working on the manhattan project. i've been given privileged access to the house by curator cheri trottier. this is the room, why the oppenheimers chose this house. so have you had more interest in oppenheimer and the house since the movie came out? definitely. there's people, as you saw, peeking through the windows. there's a great curiosity about where did this man live? this was oppenheimer�*s study. the typewriter. yes. yeah. opened by the censor as well. because it was all so secret. yes.

everybody�*s mail, coming and going, was censored. oppenheimer would have meetings in here with other scientists? this would be a room in which a huge amount went on? people were invited here for dinner, and oppie served his very strong martinis. there are stories where people literally had a very interesting time trying to leave and walk upright. the basics of nuclear weapons hasn't really changed since the first bombs were developed in the 1940s. they are still based either on fission, which is the splitting of atoms to release power, or they are based on fusion, which is the fusing together of atoms to create power. what we think of as a nuclear weapon is actually a number of different components. so there is a warhead, which is essentially the bit that goes bang. that contains the fissile material, whether it's uranium or plutonium. the warhead has to be transported in a certain way,

and it's what we call a delivery system. so it may be this warhead may be in a bomb that's dropped from an aircraft. it may be on top of a missile of all sorts of different ranges or, indeed, it could be in a whole host of different ways as well. archive: that's the atomic bomb exploding at nagasaki. _ all of you who see this picture can judge for yourselves the extent of the menace to civilisation of this new weapon. in 1945, the united states dropped their new weapon on the japanese cities of hiroshima and nagasaki. hundreds of thousands were killed. it changed the face of warfare. scramble!

america had ignited a nuclear arms race. four years later, russia began testing atomic weapons... ..followed by the uk in 1952. archive: after the first | blinding flash, dr penney turns round with a smile of satisfaction to view the colossal spectacle. in the �*60s, france tested... the film record has been heavily censored by the french authorities. but this picture is impressive evidence of the bomb. ..followed by china. those who now possessed nuclear weapons had the ultimate means to deter an attack, giving them enormous power. soon, the nuclear club grew. india detonated its first weapon in 197a. then pakistan developed the bomb in the �*90s. it's widely believed israel has nuclear weapons, though it's

never confirmed this. in 2006, north korea carried out its first nuclear test. the story of nuclear warhead proliferation is numbers went up exponentially. the total number of warheads that have been built is probably well over 100,000. but what we've seen over the last three decades is a gradual slowing down, a gradual reduction. however, there are probably in the region of 13,000 nuclear weapons in the world today, in the eight, brackets, nine states — most of these in the us and russia. the two bombs that were dropped in august 1945 killed somewhere in the realm of 200,000 people.

most modern nuclear weapons today are more powerful, have more explosive yield. in the uk case, probably somewhere in the region of six to seven times as powerful. and many of the other states have warheads that are more powerful still. so even just a handful of those could probably destroy the uk. the explosions at hiroshima and nagasaki, and the radiation sickness that followed, showed the true horrors of nuclear weapons. oppenheimer was haunted by his creation. the world would not be the same. i remembered the line from the hindu scripture of the bhagavad gita. "now i am become death, the destroyer of worlds." i suppose we all thought that, one way or another. the manhattan project scientists who created the bomb felt compelled to warn the public.

they came up with the idea of the doomsday clock... ..to visualise how close we are to destroying our world. the mushroom was becoming an acceptable fungus in man's garden. a group of scientists tried to waken the general public from this apathy and founded a periodical in which they tried to explain the social and political consequences of atomic power. its cover design became a clock approaching midnight. as the time for atomic scientists and the world ran out, its hands neared the end of time. when it was first set in 1947, the hands stood at seven minutes to midnight. they've moved 25 times back and forth since then... ..in the 1990s to the furthest point, 17 minutes away, when the soviet union broke up. by 2017, with putin and trump in power and north korea's kim

jong—un, the hands went forward again to two and a half minutes. today, on top of the nuclear concerns, climate change and threats from new technologies like ai are part of the assessment. in 2023, the hands moved the closest they'd ever been to midnight. just 90 seconds away. i've come to chicago, where the bulletin of atomic scientists is based. reporter: north korea has threatened to detonate - a hydrogen bomb over the pacific. president putin has ordered russia's strategic nuclear forces to be placed on... the president warning the risk of nuclear armageddon - has not been this high-

since the cuban missile crisis. the bulletin�*s president is rachel bronson. nice to meet you. very nice to meet you. so this is the bulletin? this is the bulletin. bulletin of atomic scientists covers. yeah. they go back 75—plus years. this is the original doomsday clock. so that was the very first iteration of the clock. that's it, right there. it was created by an artist. and it's a metaphor about how close we are to destroying humanity with our own technologies, with our own making. this was the late �*40s. countdowns, clocks, rockets, missiles. this was very much... this was a dangerous time. yeah. they saw the potential of a global arms race. they really believed that if you could educate the public, the public would put pressure on leaders, and leaders would have to keep us safe. why did you make the decision

in 2023 to move that clock to 90 seconds to midnight? it was largely around the russian invasion of ukraine, which our science and security board deemed as one of the most dangerous times in history. why? first of all, the us and russia control 90% of the nuclear weapons on this planet. now, a nuclear power state using nuclear weapons as a tactic, as a terrorism, psychological terrorism, but also potentially as a tactic. they were threatening to use nuclear weapons. you're talking president putin, russia. that's right. and so that was the first time in a very long time that we could remember such threats, and them being bandied about so casually. and so it was a very, very scary time. and the likelihood of misperceptions and accidents were so high that, largely for that reason, they moved

the hands of the doomsday clock closer to midnight. explosion. shouting. the russian invasion of ukraine was a war president putin expected to win quickly. that didn't happen. ukraine fought back with weapons supplied by britain and other nato allies. just days into the conflict, president putin made a threat that shocked the world. translation: top officials of leading nato countries i are making aggressive statements about our country. therefore, i'm ordering the minister of defence and the chief of the general staff to put the strategic nuclear forces on special alert. putin's warning to the world

not to join the fight alongside ukraine revived fears of nuclear war not seen since the 1960s. i've come to geneva in switzerland, a city associated for many decades with efforts to bring peace... ..and now home to one of the main united nations offices. pavel podvig is a russian expert on weapons of mass destruction and russia's nuclear forces. nice to meet you. for a decade, he was involved in setting the doomsday clock. the russian president made it very clear that nuclear weapons are on the table. he said very specifically that if someone would intervene, then they will see the consequences they've never

seen in their lives, which was a direct reference to nuclear weapons. how shocked were you that president putin would say that at that time? oh... that was pretty shocking, i would say. at that point, we didn't know what that would look like. i wouldn't say we've never seen before, because if we go back to, like, �*62 and the cuban crisis, we may have seen things of that order, of magnitude, but imagine this happening in the 21st century. that was definitely a shock. and president putin — why did he do this? and what does it tell us about him and how far he might be prepared to go? well, this is... ..exactly what nuclear weapons are there for, to make sure that you have a certain freedom of action. and at that time, apparently, the russian president believed that by making these

statements, he could deter the west from intervening on the side of ukraine, which was a correct calculation. this is how deterrence works. but do you think there's a danger that if he was backed into a corner, if there was an existential threat to russia, that putin could use nuclear weapons? well... ..technically, yes, the weapons are there. merci beaucoup... so the only way russia can use nuclear weapons in this conflict is to use it in what i would call a strategic sense, or in hiroshima and nagasaki sense, to shock the opponent into surrender. ukraine, in this case. the reaction of the internal community to just the idea of nuclear threats was very strong, very negative. people didn't like it, and they did force russia to lower the rhetoric.

and it was clear that bringing nuclear weapons again, even as a threat, will definitely not... ..bring russia any friends. this isn't the first time the world has held its breath over the prospect of nuclear war between russia and america. a sea of planes that on a moment's notice can be in the air to avenge any communist strike. in 1962, russian missiles in cuba raised tensions to boiling point. it shall be the policy of this nation to regard any nuclear missile launched from cuba against any nation in the western hemisphere as an attack by the soviet union on the united states. at the 11th hour, the crisis was averted. but that close call sparked the need for better global cooperation on nuclear weapons. in london, representatives of three nations signed

an agreement to halt the spread of nuclear weapons, taking out an insurance policy, so to speak, against a worldwide nuclear holocaust. in 1968, the non—proliferation treaty was signed. it's still enforced today. it was meant to restrict the nuclear weapons club to just five — the us, russia, britain, france and china. other countries agreed to only develop civilian programmes like nuclear power plants. under the npt, most countries agree not to develop or seek nuclear weapons, and they accept safeguards by the international atomic energy agency to verify that all of their nuclear activities are strictly peaceful, that no nuclear facilities

or nuclear materials are being used for weapons purposes. it basically provides stability in the international system, in the global nuclear order. the treaty limited the number of countries that developed nuclear weapons. but the �*70s and early �*80s saw a massive arms race between the two major players, america and russia. during the cold war, they ramped up the number of nuclear warheads to over 70,000 between them. the fear was they could set off an all—out nuclear war with devastating consequences. the enemy realises that an attack on the united states would likely mean committing national suicide. nobody wins in nuclear war because both sides are sure to suffer terrible damage. during the cold war years, we were constantly at loggerheads. we had a lot going on to try to get our hands around

the threat of nuclear weapons and the threat of nuclear holocaust, because it is an existential threat to humanity. it was something both the soviets and we, later the russians, felt we just had to keep working on. then the world changed. a new russian leader, mikhail gorbachev, came to power. reporter: the world had waited six years for this moment, - and yet mr gorbachev�*s first words were easy—going and natural. "dobriy den," he says. "good morning." gorbachev and president ronald reagan met at a historic summit. shortly after, the two superpowers signed the start treaty, a commitment to reduce the number of nuclear weapons. the cold war was over and a new era of arms control began. that was really an incredibly promising time because the cold

war had ended and we had this opportunity to rethink the role of nuclear weapons in us policy, and to greatly reduce. and nuclear weapons were greatly reduced over that time by a total of about 80%. in 2010, us president obama signed a second start treaty with russian president medvedev to reduce their stockpiles still further. i was responsible for negotiating the new start treaty. it causes us to limit our deployments of nuclear warheads to 1,550 warheads each. was a bit of a golden moment, i would say, in the us—russian relationship, and we were lucky to be able to get the new start treaty negotiated during that period. medvedev was president, but the real power in

the kremlin was the then prime minister, vladimir putin. i know for a fact that behind the scenes, vladimir putin was trying to throw a wrench in the works. it was, i think, difficult sometimes to get things across the finish line in moscow. but in that way, it was a typical arms control negotiation, each side pushing for its own national interests. we got it finished, and it did enter into force. today, president putin's invasion of ukraine, and his nuclear threats, have brought cooperation with america to a halt. translation: military chiefs told russia's leader the task. of delivering a massive nuclear strike by strategic offensive forces had been rehearsed.

the new start treaty runs out in 2026. at present, there are no negotiations to extend it. that could spell the end of over 30 years of agreement between the two major nuclear players on limiting their weapons. we are no longer conducting onsite inspections or really exchanging information that provides both sides a great deal of predictability about nuclear weapons systems on the other side. so to me, it's a tragic moment for nuclear arms control. this is a very dangerous time. we have moved from a period where nuclear weapons were considered unusable and a nuclear war unwinnable. we're seeming to move into a period of time where we're not so sure. every major country is investing in their

nuclear arsenal. hello. cloudy, windy and mild pretty much covers sunday's weather forecast in most parts of the uk. we do have this wriggling weather front which will bring rainforsome, particularly in the western side of scotland. but with that front edging a little bit further northwards, it will introduce milder air for more of us. but with that extensive cloud cover, it will be quite misty and murky for some coasts and hills.

a bit of rain across north—west england, parts of northern ireland, but more especially, this western side of scotland, the rain becoming heavy and persistent. eastern scotland with a bit of shelter from the winds, while here, we mayjust see a little bit of sunshine. but it is going to be a windy day for many of us. very windy in the far north. gusts of 60 miles per hour, for example, in shetland, where temperatures will only climb to four degrees. but elsewhere, further south, highs of 13 or 14 degrees — well above the average for early—february. and then during sunday night, the rain keeps on coming in western scotland, hence this met office yellow weather warning. the wettest locations over higher ground could see 170 millimetres of rain. some snow mixing into the north of our weather front, where it engages some cold air. very mild, though, further south, as we start monday morning. through monday, we'll continue to see these outbreaks of heavy rain just waxing and waning across the north—west of scotland, with some snow across the far north. but to the south of that, it stays mild, it stays quite

windy, it stays very cloudy, with some mist and murk and some spots of drizzle. temperatures up to around 13, maybe 14 degrees once again, but always colder to the north of our weather front. just two degrees there, in lerwick. and by tuesday, well, that frontal system looks set to push a little bit further southwards. so rain for northern ireland, northern england, perhaps into north wales. to the south of that, still cloudy, a bit murky, very mild. to the north of our weather front, well, some sunny spells, a few wintry showers in the far north and something just a little bit chillier. now, this weather front just wriggles around through the middle part of the week. it will bring further outbreaks of rain. later in the week, it does look like these various frontal systems will eventually push southwards and that will allow some colder air to dig its way across more parts of the uk. it is going to take a while for that colder air to spread southwards, but it does look like, as we get through the end of the week and into the weekend, it will turn colder for all of us. yes, there'll be some rain, but for some, there may also be some snow.

live from washington. this is bbc news. the us and uk lead international airstrikes on iran—backed houthi positions in yemen — in the latest response to attacks on red sea ships. it comes a day after the us hit iraq and syria with airstrikes in retaliation for last weekend's deadly drone strike on us troops injordan. presidentjoe biden saunters to victory in south carolina, where democrats held their first primary election of the year. hello, i'm sumi somaskanda. we start in the middle east, where the us and uk have led more coalition strikes against the iran—backed houthis in yemen. this video from us central command shows american aircraft taking

off for the raids. according to centcom —