on that bottle, you know. and acid just comes on my face and i'm totally blind. andreas christopheros was attacked with acid two and a half years ago. and, a special report on a new project offering hope to drought stricken parts of africa. i'm inna modja. a musician and activist from mali. i campaign for human rights, here in my homeland. in a generation there has been a catastrophic change in the environment. good evening. korea and its surrounding region are in a state of high tension tonight. president trump this morning tweeted that us military options were "locked and loaded". north korea maintains that it intends soon to fire four missiles in the direction of guam, with its american base. but we're also hearing moderating voices. james mattis, the us defence secretary, has stressed that the us is dealing with the north korean threat by diplomatic means and that war would be "catastrophic." and it emerged today that talks are actively taking place between president trump's korea envoy and a senior north korean official at the united nations in new york. so, are wiser heads prevailing? it's possible. but there are bigger issues here that won't go away. at the end of a week of high bluster, i've been looking into the broader question of whether the use of nuclear weapons is genuinely becoming more thinkable. there's a real chance of military action between nuclear armed countries and that's very rare. it also comes at a time when many experts feel nuclear war is growing more likely. during the cold war, it would have been the soviet union and the united states, both with thousands of nuclear warheads and if god forbid if they'd gone to war the whole planet could have been destroyed. now, if you had, and we must desperately try to prevent one, if you had the use of nuclear weapons, either north korea, india, pakistan or the middle east, disastrous for these regions, but compared to the cold war, the risks at the time of the cuban missile crisis, it wouldn't threaten the very existence of the planet. what korea reminds us of is proliferation and the more widespread these weapons are, the greater the scope for use or accident. pakistan and israel are each believed to have more nuclear weapons than britain. india has them too and iran, saudi arabia, syria and libya are all believed to have had nuclear weapons programmes, some of course halted. the next threat is what experts call lowering the nuclear threshold. that means, to some, their use is becoming more thinkable, in circumstances short of global nuclear war. recent russian exercises reportedly involved a small scale use of nuclear weapons against european countries. in the us, meanwhile, donald trump hinted on campaign, that they might be used against the islamic state group. were a conventional conflict to happen again, where north korea could probably inflict a lot of damage, it certainly wouldn't be able to prevail in a straightforward, conventional military scenario. which is where nuclear weapons come in for north korea in part, because those weapons give north korea what we would call an asymmetrical capability. even if wiser heads prevail, what is the scope for accidental nuclear war? several senior cold war statesman campaign on this issue, highlighting concerns that computer glitches or cyber attacks could trigger armageddon. and if all that isn't worrying enough, there's the question of whether some countries might have cut conventional forces to such a degree, that they have few other options. some countries that pursue nuclear weapons, pursue them because they are conventionally inferior to their adversaries. so nuclear weapons in a conflict scenario might come into play much earlier because their incentives to keep the conflict conventional, where they'd probably lose are low. a stable nuclear balance, like the cold war or the india, pakistan situation is underpinned by large conventional forces. that's the anti—imperialist case for proliferation, if you like, that buttressed by other forces and rational leadership, it can stabilise regions. in the case of india and pakistan, what has happened, and it is disturbing and uncomfortable to acknowledge this, they went to war. they had a real wars three or four times before they both got nuclear weapons. and since then that has acted as a discipline, as a constraint. that's perhaps the biggest military unknown in this present crisis. the us could mount strikes no doubt, but kim jong—un has a wide variety of retaliatory options, from massive conventional attacks to chemical, biological and nuclear weapons. no wonder key allies from south korea to australia are worried. joining me now is gary samore. he was the white house coordinator for arms control under president obama and he's now at harvard's kennedy school of government. we will look at some of those big issues on the on thinkable in moment, but let's start off with north korea, the issue of the moment. you have been dealing with this on and off for decades. where do you rank this situation right now, how serious? i continue to think the risk of actual war is low because nobody would benefit from it. for north korea, it would be fatal and for the us and its allies, it would be costly. but we are seeing a lot of posturing and i hope it is a prelude to eventually resuming negotiations. a lot will depend on kim jong—un‘s calculations. he has demonstrating long—range missile capability, but the cost has been more serious economic sanctions, which the chinese have been as serious to support. at some point when kim jong—un decides he can come back to the bargaining table with a strong position and look to see what he can get in return in return for accepting a freeze on his nuclear return. we are not there yet, kimjong—un of thing he cannot be intimidated by the security council. so i think we will see another round of missile tests but i think they will be short range tests. it would be extremely provocative? it would, but at the same time with the trump administration, they are trying to manoeuvre towards a resumption of diplomacy. rex tillerson has said if kim jong—un would just pours his testing programme, the us is prepared to open talks. we know there are low—level talks going on between the state department and north koreans and new york. you were part of the conversation in the obama white house. iran was a big priority, there were many other things going on, to what extent do you think it is fair to say the north korean was pushed onto the back burner under obama? i would say the obama administration took several runs at an effort to negotiate with north korea and they all ended unhappily. the first run ended after the sinking of a south korean vessel. then the second ended after a league date agreement in february 2012, where the us provided humanitarian assistance and the north koreans agreed to suspend testing and freeze their nuclear programme but then kim jong—un violated the agreement three weeks after it was done. so the conclusion was there was no valley in talking to north korea until more luggage was built up. but the missile testing continued and unchecked ? you have seen two processes happening at the same time. kimjong—un has has accelerated his testing programme and the sanctions have begun to build up. you mentioned the likelihood of reverting to the diplomatic to approach, you quoted rex tillerson, but how do we read the statements from president trump? the others all seemed to be behaving like the washington figures, like yourself, that we are used to, but this is different. is it dangerous in itself? in substance, trump is not saying anything different that president is always say in that america will defend itself and its allies. but trump is doing it in a way which has a locker room quality to it. my concern is, i would hate to see the president of the united states putting himself in a place where he's being equated with kimjong—un. the north koreans are famous for their blustering. he's being equated with kimjong—un. it is important trump does not go too far in terms of making our allies nervous. there is some value in making the chinese nervous, to get diplomacy started, but if you go to bar with that rhetoric... you have spent a lifetime working on proliferation, so is itjust delaying the inevitable, that other countries will get the bomb and then one of them will use it? i think in some cases countries have made the decision to give up the nuclear weapons programme. south africa has given up nuclear weapons programmes, south korea, taiwan. other efforts fail, pakistan, india, north korea. so you never know, when you start, whether it will succeed orfail. you have to play out your hand and then at the end of the day, you will know. thank very much. acid attacks are on the rise across the uk. there were more than 400 in the six months up to april 2017 in england and wales, and the numbers have more than doubled in england since 2014, the majority taking place in london. most reported attacks have taken place in public places, but newsnight has spoken exclusively to one family who were victims in their own front room. elaine dunkley reports, and herfilm contains images some may find disturbing. where does it hurt, mate, are you all right? we're here to try and get water into your eyes. mate, keep your eyes open, keep your eyes open. the use of chemicals as a weapon is growing in the uk. victims left physically and mentally scarred by acid attacks. i was thinking, i'm not going to see anything after that. a common household product widely available and used in the most horrific way. back in april, 20 people were left injured and two blinded following an acid attack in this nightclub. and we've seen it on the streets. thieves on scooters throwing acid and people to steal mobile phones and handbags. and now it's happening in people's homes. zahadine barba was attacked in his living room three weeks ago. i'd just put an ad on gumtree. selling the phone. showed the phone to him and he said yes, i'm happy. and grabbed a bottle out from his bag and he just pressed on that bottle, you know. twice on my face, and acid comes on my face and i'm totally blind, and i know that he attacked me with acid. fortunately zahiruddin was able to wash off the acid. he has no visible scars and has regained his sight but his family has been left traumatised. i went to the kitchen and then i saw my dad over there, shutting his eyes. and you know, like, putting the water on his face, and then i ran off to the garden because i really didn't want to see that attack, i really didn't want to. i was in shock. this is horrible. i never had anything like this before happened to us. and how are you now, how are things now for you? 0h, very good now. just not thinking any more. yeah. recent attacks have brought into focus the urgency in helping someone who has been a victim of this sort of crime. and although it is still very rare, the royal college of emergency medicine is calling for more training of members of the public. this is newham university hospital and it's in east london. this area has the highest number of acid attacks in the uk. in the past five years there have been 400 cases and that is increasing all the time. we are seeing a case about every day or two, especially in this area, it seems to be a lot more frequent. and some members of the public, what should they do if they see someone with eyes burning, skin burning, what do you do. it's important to stay safe as a bystander, make sure you don't become a second victim. other than that if you can help the person by rinsing the acid off them and tap water is good for that but you need a lot of it. i would recommend using 30, a0 or 50 litres of water to get rid of the acid from someone‘s face. this is extremely important, you can make a difference to whether someone can walk away from an acid attack with just a superficial burn or be blinded for the rest of their lives. the problem is reflected across the uk. there were 400 attacks carried out. attacks carried out in the six months up to april 2017. london remains the worst area. since 2011 there have been nearly 2000 attacks in the capital. there are petitions online to restrict the sale of industrial acid. it is cheap, easy to obtain and disguise. it is a challenge for those trying to take it out of the hands of criminals. i think it's far too easy for people to get hold of it, whether in a domestic setting or retail setting. but one thing that is important to say is that it is still relatively rare. one of the things we are doing now is, we are looking to do pre—emptive testing to identify where people carry that acid, we are also working closely to send strong messaging around the implications and the impact. if you choose to carry acid you can be liable for a four—year imprisonment sentence for carrying it is an offensive weapon. if you use and the courts can sentence you to life imprisonment. so the penalties are very severe and it's important that anybody that goes out with acid, whether carrying it or whether they use it, that they understand that because we will be coming after you. victims want tough words to become a reality. for those who have been left scarred, their injuries are a life sentence. elaine dunkley reporting. i'm nowjoined from truro by andreas christopheros. he suffered serious burns when a beaker of sulphuric acid was thrown in his face. it happened on his own doorstep two and a half years ago. his attacker, who mistook andreas for his intended victim, was jailed for life, but that sentence has since been reduced on appeal. andreas, we are grateful to you for coming in to talk about this. it cannot be easy. when you see how much coverage has been attracted by this issue of late, do you think the rest of us have been too slow to wake up to the seriousness of this? i think it has become very shocking, shocking matter for the country. it is hard to see what the solution should have been but i believe that the real solution at this time is tougher sentencing. and with my attacker having his sentence made lighter, it seems completely wrong. you have been through so much, and trying to get your life back on track, do you feel that anyone who says that this is not as serious as i've broken attack is wrong? i would have preferred to have been shot or stabbed. 0n the first might might doctor sat down my wife and my mother back and said, we do not think he will make it through the night. the difference was that if i was shot or stabbed the wounds would heal, the scarring caused by sulphuric acid which was what i was attacked with, i will never heal. i will have these scars for the rest of my life. i'll will forever have a loss of sight. there is no miracle cure for me. i'm sure you have heard in recent months, all sorts of ideas have been put around like stopping people under 18 buying corrosive liquids, saying you have to do it with a credit card, changing sentencing guidelines, which of these ideas make the most sense to you? you can buy sulphuric acid in such an easy manner. someone wanting to get their hands on it, they will. and ultimately i think the real deterrent for anyone thinking about committing an acid attack or an attack of any corrosive substance should be the sentencing. you recently met with your mp, who is also a home office minister. do you get the feeling that the government is giving this type of crime the attention it merits? it is nice to hear this week the suggestion that any person who does commit an acid attack will receive a life sentence. i think the indicators are there. i feel everyone is on the same page now. it's only in the last week or so that i can say i've felt like that. but anyone who commits an acid attack should face life. it is a life sentence for me. they should face life, minimum term of 25 years. i will have my injuries until the grave so why should they walk the streets? thank you for putting that view to us. thank you, andreas. well, we've been dealing with some tough issues tonight, but bear with us, this last story has a more hopeful note. climate change poses huge challenges and, it's projected, will cause hundreds of millions to become refugees. desertification in sub—sa ha ran africa plays a big part in that. and that in turn feeds into europe's unfolding migrant crisis. inna modja is a malian singer and activist who has been to senegal for newsnight to witness a pan—african initiative, called the great green wall. it aims to improve livelihoods in the sahel region, reverse desertification, and break the cycle of exodus. here's herfilm. stretching across the width of africa, the southern reaches of the sahara desert are known as the sahel. it's a zone between sand and productive land, which has been severely degraded in recent years by climate change and desertification. but here in northern senegal, the sahel is starting to come back to life again, thanks to a little—known pan—african initiative called the great green wall. launched in 2007, it hopes to provide a new way of thinking about the african migrant crisis. i'm inna modja, a musician and activist from mali. i perform my music around the world and campaign for human rights here in my homeland. the great green wall was initially conceived as an ambitious plan to plant a natural 8,000 kilometres wall of trees and plants stretching from senegal to djibouti, but that hasn't happened and the grand idea of a continuous wall of trees has gradually faded. critics argued that a wall promoted the idea of a barrier against the desert, when in fact it's a much greater region that needs restoring. so, the wall has evolved into a vision to green the areas surrounding the sahara with a mosaic of trees and small developments, like this market garden. this has been a shared political vision of african leaders for generations. notably thomas sankara, burkina faso's revolutionary leader in the 1980s. now 20 countries across the region have come together to support the initiative. $8 billion have been given or pledged so far, mostly coming from international partners, such as the world bank with some funding from beneficiary countries and the african union. people here live on the very front line of climate change, not in some abstract reality. but in their day—to—day lives, they feel the effects of climate change, they feel the effects of desertification. this project really aims to redress this by creating food security for people who are food insecure. and it's notjust about food, every day we see the wider impact of land degradation in the sahel. the mediterranean migrant crisis, the boko haram massacres in the chad region and terrorist attacks in mali and burkina faso. at their root, all of this can be traced to a cycle of poverty and lack of opportunity that is fuelled by a decline in natural resources. in a generation, there's been a catastrophic change in the environment. the land feels dead here. there's no birdsong. nature itself is being extinguished. the great green wall aims to provide new opportunities for communities, not just to survive, but to thrive here once more. places like this in senegal are known as the villages with no men. there's a gaping hole in the local demographic. the young men have left to seekjobs elsewhere, as agriculture is no longer viable. it's driving the young away from their communities to seek opportunities far afield. i can see that you have henna on yourfingers, so do you do it yourself? this lady has not heard from her son for years. he was the major breadwinner for the family before he left. have you ever heard any news of him? how does that affect you economically? it only takes a walk through the dusty street here to see whose relatives have made it to europe and whose haven't. the homes of successful migrants are large properties made of concrete and breeze block. the others are wood and straw with thatched roofs and flimsy fencing. this is the pull factor that drives many towards the perilous boat journey across the mediterranean. in west africa up to 80% of the population live in rural areas. youth unemployment is a huge problem across the sahel and a massive driver of migration. as ever, the targets are huge. by 2030, the project aims to restore 100 million hectares of land, sequester 250 million tonnes of carbon and generate more than 350,000 jobs in rural areas. although it's not clear exactly how these numbers will be achieved. it's definitely small beginnings, with the hope of building to a biggerfuture. the great green wall is a powerful symbol to focus global attention on the problems in the sahel.