hello, everyone, and welcome to "amanpour and company." here's what's coming up. a caravan of 7,000 migrants bears down on the united states through mexico and president trump is accused of manufacturing midterm hysteria. we get the latest on the ground, and we speak to the former mexican foreign minister jorge castaneda. then, is america losing its longest war? i speak to stanley mcchrystal, former commander of allied troops in afghanistan. and our walter isaacson probes the origins of life, the universe and everything with theoretical physicist, brian green.

>> uni world is a proud sponsor of "amanpour and company." when v. coleman found add collection of unique hotels, she had bigger dreams and those dreams were on the water. a river, specifically. multiple rivers that would one day be home to uni world river cruises and their floating boutique hotels. today, that dream sets sail in europe, asia, india, egypt, and more. bookings available through your travel agent. for more information, visit uniworld.com. >> additional support has been provided by -- rosalyn p. walter. bernard and irene schwartz. sue and edward wokenheim iii. judy and josh weston. and by contributions to your pbs station from viewers like you. thank you. welcome to the program, everyone. i'm christiane amanpour in

london. an estimated 7,500 migrants are heading north through mexico fleeing violence and poverty in guatemala and honduras and hoping to reach the united states where they plan to seek asylum. reporters on the ground say the migrant caravan consists of thousands of families including many mothers and children facing starvation and attacks on the long march north. reporters and aid agencies see a full-blown humanitarian crisis developing, but president dronad trump lashed out in now-familiar terms especially ahead of midterm elections. >> going to the middle of the caravan, take your cameras and search. you're going to find ms-13, you're going to find middle eastern, you're going to find everything. >> but a senior counterterrorism official contradicted trump's insinuation saying we do not see any evidence isis or other sunni terrorist groups are trying to

infiltrate the southern u.s. border. correspondent bill weir has been following the caravan. he's joining me now from mexico. bill, thank you for being with us. this is a gathering storm and a humanitarian crisis. what are you seeing on a day-to-day, step-by-step basis there? >> reporter: christiane, just imagine if you or someone you know had taken everything you own and you could carry on your back and has walked hundreds and hundreds of kilometers. sometimes carrying your children. accepting food from people like this man handing out tortillas here, and 13 days into the journey, how would it feel? so it is a day-by-day, minute-by-minute pursuit for survival. that's what forced a lot of them initially to leave honduras there and walk for the last 13

days. they have about a month or so, at least, before they reach the western united states border as well. but i'm seeing mostly people -- i'm seeing a lot of scenes like this where the kindness of mexican strangers is helping feed and clothe these people as they make their way north as well, and, of course, the idea that there are hidden. muslim terrorists in this crowd is ludicrous on its face. you know, what the president could equally point out is this group is 99.9% christian, catholics, and protestants alike. and many of them fleeing both political and criminal violence in honduras, others fleeing poverty. those who see the safety in numbers of this crowd moving north, in mexico, whether they are, or guatemala, are deciding to join. it's an opportunistic sort of thing. there's strength in numbers.

most are oblivious to the fact the optics are playing out politically in the united states. they don't have the luxury to think in those terms. i've been asking people, first of all, do you know you're breaking the law? they acknowledge they are but say they have no other choice. then i was reading the president's tweet s to some fols in the crowd yesterday. here's one reaction. he's using the pictures of the big caravan saying it's a mob of criminals, and there's even middle eastern possible terrorists in there. "i don't understand why he's saying that," he says. "we're not terrorists. our country is very violent, but the people are poor people." do you have children? "that's what hurts me the most, is i have three kids and i had to leave them behind because there's no job." when do you think you'll see them again? "i don't know," he says. "it's up to god."

now the caravan has halted here in this town about 80 kilometers north of the mexico/guatemala border, 50 miles or so. not out of fear of law enforcement or anything other than to honor one of their own. one man from honduras fell from an overloaded truck on the highway yesterday, fell to his death. the second confirmed death thus far so they paused to respect him and tell us they will head back north before the crack of dawn tomorrow, christiane. >> bill, they do really seem determined. i'm wondering why this is suddenly happening right now. we've seen periodically over the months and years that there are these long marches out of, as you describe it, poverty and violence and corruption at home. and what has triggered the latest one? honestly, we're seeing desperate pictures even on the mexico/guatemala border of people hurling themselves off bridges, trying to get on to anything that floats to take them on to mexican territory.

>> reporter: yeah, we were on the bridge when the mexican federales tried to stop the flow. didn't work very well. people jumped from the bridge, swam or rafted across there as well. the best i can gather is really the initial spark of this caravan came out of the political climate that's happening in honduras. as the audience might recall, very contested election. juan hernandez, the president, was re-elected in what international election watchers say was very suspicious terms. there was a weeks-long recount. during that recount president trump congratulated him, promised him foreign aid as well, and then once in power he's taken on more of a strongman stance down there appointing a lot of his cronies into the judgeships as well who drop charges against people accused of embezzling massive amounts of that country's wealth. they say 22 protesters were killed according to human rights watchers down there.

that plus the cartel violence sparked the initial caravan to come out. and then it just gathered steam as people see this as an opportunity to find strength in numbers and comfort as they head north, as they support each other. people from different countries are now sort of this brotherhood of the caravan as they move north, again, most of them oblivious to how it's playing in the country of their destination. >> bill, i'm really curious to know they may be oblivious how it's playing politically but they must have seen over the last months these awful scenes at the u.s./mexico border when families were separated. the last big crisis was that one, and i wonder don't they think that might happen to them? you've been reporting so many kids are on their way as well. >> reporter: yes, i've said again and again, do you understand what's happening in the united states? have you heard about family separations? have you heard about president trump's threats to use soldiers to turn you away? and all of their answers sort of

harken back to an amazing poem by a somali-english poet who wrote, "you only leave home when home is the mouth of a shark. you only run for the border when you see your whole town running ahead of you. you only put your kid in a boat when you think the water is safer than the land." they say we'll take that choice, that uncertainty, that 5,000-kilometer hike up the length of mexico with all the perils that go along with that. they'll choose that path rather than stay at home. >> it is extraordinary and the way you read that poem it does put it into sharp relief. bill weir, thank you so much. and now to the former mexican foreign minister jorge castaneda. he says if the people marching want to claim asylum in the united states they should be allowed to cross through mexico. he's joining me now, in fact, from new york. mr. castaneda, that is pretty provocative. you're basically saying, hey,

you want to go to the united states, go through mexico and you should be able to get to your destination. >> absolutely, christiane. good to be with you. it's very important to understand that the united states has been pressuring mexico for several months now for mexico to agree to what president trump said. that is that asylum should be requested in mexico. but mexico has not agreed to that, and it shouldn't agree to that. some people want to request asylum in mexico, about 1,000 have. those requests will be processed. some will be granted. others not. but other people don't want to stop in mexico. they want to go to the united states. mexico should not be doing the united states' dirty work for it. these people should be allowed to reach the border, request asylum to american authorities at the border, and the united states will decide what it wants to do. there is no reason for all of them to be processed in mexico except that that's what president trump wants.

that's not a good enough reason. >> well, what about, i guess, the duty of care toward a lot of these migrants? you've seen with your very own eyes those who get to the border certainly over the last several months under this administration have been, you know, detained, have had their children separated, this whole zero tolerance policy, which i admit has been retrenched under a lot of protests. there are huge numbers of kids who are still separated from their parents. why would any government encourage this caravan to keep moving? >> it's not a question of encouraging it, christiane. they entered mexico. the mexico/guatemalan border has been porous for 50 years at least. more than 50,000 entered in the 1980s fleeing the civil war in guatemala. this is not a new story. people come and go every day

across the river on these rubber rafts or swimming or whatever. so now a group of central americans got together and instead of traveling alone and being much more vulnerable to rapists, assault, shakedown people, the mexican authorities, which on occasion are very corrupt, they decided to band together and in numbers there is safety. this is not for the mexican government to decide what it should do with them. can you imagine if we in mexico were to put them in refugee camps and not allow them to leave? you remember the images in hungary of the syrians? >> yep. >> you remember the images in austria. we don't want that either. why should we do the americans' dirty work? either they process these people in honduras, which they could, or they process them on the u.s. side of the u.s./mexican border, not in mexico. >> so, in a way, these people are political footballs wherever they are. they're footballs on the u.s./mexico border. they're footballs in their own country where they are fleeing, by all accounts, a huge amount of corruption including under

the latest elected president of honduras. so a couple of questions. in terms of the law, you say we don't want to have refugee camps set up but the u.n. secretary-general is urging all parties to abide by international law including the principle of, quote, full respect for countries' rights to manage their own borders. the refugee agency says it's deploying teams to ensure travelers are fully informed regarding their rights to asylum along with providing legal advice and humanitarian assistance. they may very well have to end up putting up camps. >> well, for those who request asylum in mexico, and, as i said, more than 1,000 have, and the mexican government is apparently handling this in a very humanitarian way after an initial mistake of tear gassing the women and children on the bridge. now they're doing this properly. unhcr is helping, which is a

good thing. and those who request asylum in mexico should be kept in shelters while their requests are processed. those who do not want to request asylum, we have two choices in mexico. we deport them or we let them through. there is no way the mexican government, the new one or the old one, can deport 7,000, 8,000, 9,000 people who are now only 100 miles from the border. i think the important thing, christiane, is to view this from a humanitarian point of view. these people are fleeing the violence in what is probably the most violent city in the world outside of countries at war, san pedro in northern honduras. that's what they're fleeing from more than anything else. whatever they run into in mexico or in the united states is better than that. i can only congratulate bill weir for this excellent verse from the poet he mentioned about the shark. i think he got it just right. >> and, you know, mentioning bill, he also said and reminded

us when this president was elected in honduras, president trump praised him and congratulated him and the administration promised a lot of aid. now president trump is basically saying that -- in fact, why don't i just play what he said about the issue of aid? i'm going to play this sound bite. >> sure. >> guatemala, honduras, el salvador, we pay a lot of money. every year, we give them foreign aid. they do nothing for us. nothing. they did nothing for us. so we give them tremendous amounts of money. you know what it is. you cover it all the time. hundreds of millions of dollars. they, like a lot of others, do nothing for our country. >> so he's threatening to take away that aid and using terms that you're now familiar with. but what does that mean in the macro picture, threatening to take away aid? what will it do to this flow of caravan? >> first of all, christiane,

it's very little money. it's what's left of vice president biden initiative called alliance for prosperity for the three countries, actually the five countries in central america which have been gradually reduced over the first two years of the trump administration. there's not a whole lot left. it's not that much money. for you and me it is but for big countries or relatively big countries, guatemala has a population of 18 million people, it's not that much money, firstly. secondly, to cut it off is completely counterproductive. the money was sent there in the first place by the obama administration initially to help people stay in honduras and guatemala and el salvador, help people be more secure. help people against the gangs, against the kidnappings, against the extortion, against the violence. you take that money away. all trump is going to do is encourage more caravans which are, by the way, said to be already leaving honduras and el salvador as we speak. and it's logical.

why is it happening now? i know you asked bill weir, christiane, and i think it's worth adding to what he said which was quite right. this has been -- the numbers have been increasing for the past three months. september was the month of the greatest number of central american families together reaching the u.s. border. it's not that all of a sudden a lot more people are coming. it's that a lot more people are coming together because it makes much more sense for them to protect themselves and also to make it more difficult for mexican authorities either to shake them down. we have corrupt authorities in mexico, christiane. you and i have spoken about this many times. it's senseless to deny it. well, these people are protecting themselves from that and they are also placing the mexican government in a very difficult situation, we have to agree to that. trump is pressuring them on the one hand. you stop them. and public opinion in mexico, bill again has been showing

this, the mexican townspeople along the way are helping them with blankets, with water, with diapers, with tissue paper, toilet paper, tortillas, what have you, because they feel a great deal of empathy for them. there may be others in mexico who are not so happy, but the townspeople are going to be the same thing, people are going do be helping them and supporting them. so the mexican government can't just all after sudden try and throw them out. there's no way. it can't happen. >> let me quickly ask you to react to what president trump also said, if you take your cameras, you're going to find ms-13 and middle eastern people. i mean, his own counterterrorism officials have said that there is no evidence of that. but are you concerned at all this might be a conduit for any kind of terrorism or anything like that? >> i don't think so at all, christiane. began cooperating with the 11. united states with the bush administration the next day on

security and over these now 17 years there has been not a single incident of terrorists trying to enter the united states through mexico or trying to enter mexico through the land border with guatemala. and the last place they would want to hide, so to speak, is in the middle of a caravan where they have to walk in 30-degree heat or 90-degree heat many american terms and walk for 1,500 miles and be exposed to everything that has happened. why bother? they can get on a plane in tapachula and fly to mexico city. >> all right. you've wrapped that up for us. >> that's pretty simple, i think. >> let me quickly end on a sort of broader issue. that's economic opportunity for people in your region. of course nafta and the whole renegotiation of the deal between the united states, mexico, and canada. i mean, we know that i think it's something like 27 u.s. states, you know, their major,

major partner for economics is mexico. the destinations there. what has nafta done or the new negotiation? is it wildly different than what it was before? is the u.s. better off? is mexico better off? how would you frame what's happened? >> i'd frame it with a huge sigh of relief, christiane, in the sense that at least there is a new nafta instead of no nafta at all which was a real threat, a real danger during many of the months of the negotiations since president trump took office. that said this new nafta or whatever anybody wants to call it is really not that different, not terribly different from the previous one and, most importantly, it will not affect neither better nor for worse the southeast. the regions in mexico that the marchers are going through, maybe through puebla, are the

poor states of mexico. the poor south of mexico. a little bit like in italy. you know, these are very poor regions where you don't have automobile plants. you don't have refrigerator plants. you don't have l.e.d. television, flat screen plants. you have people growing corn. you have people growing bananas. you have people growing nuts or some coffee sometimes. they're very poor regions. nafta ses not going to make a whole lot of difference. the absence of nafta would have been a disaster for mexico, absolutely. apparently, that has now -- that danger has gone away except, christiane, and i have to mention it, unless president trump says if mexico doesn't stop these people, i'll rip up the new nafta and i won't sign it. and i would not discard that having followed president trump closely now for two years almost. >> golly. i just was going to then ask you what you thought of the latest polls in mexico basically showing a drop of more than 30 points in positive views of the

united states between 2015 and 2017. >> well, it's absolutely logical. he as a candidate, donald trump, called mexicans rapists, drug dealers, thieves. i mean, he ran his campaign on anti-immigration, anti-mexican platform. he's doing it again right now, by the way, for the midterms. so after a lot of goodwill in mexico toward barack obama, even if obama deported more people than any other american president had ever done, there was a lot of goodwill. trump comes along and starts insulting mexicans every day. then he says he wants to build the wall. then he says he wants to rip up nafta. then he begins deporting mexicans from the heartland of the united states, christiane. it's very different to deport somebody who just crossed the border and knows he's risking

money, his life, whatever, and will try again the next day. to deporting someone from atlanta, from chicago, from new york, who has a family here, been working here for ten years, without papers, granted. he's undocumented. she's undocumented. but they've been living here. they've been paying taxes. they're law-abiding citizens. low levels of criminality. they have a job. they have a home. they have children in school. and all of a sudden they're picked up and sent back to mexico, a country they haven't been to in 10, 15, 20 years. >> jorge castaneda, former foreign minister, thank you so much for joining us. and so as the trump administration struggles with the right response to people fleeing violence and repression in these countries, so, too, is it struggling with the right response to a close ally, saudi arabia. since the journalist jamal khashoggi was killed on october 2nd inside the saudi consulate in istanbul. it's something the turkish president erdogan called today a premeditated murder. he said a plot that began in late september. >> translator: the information

obtained so far and the evidence found shows that khashoggi was murdered in a ferocious manner. to try to hide such a ferocious murder would be an insult to the conscience of humanity. so we expect appropriate actions from saudi arabia. from this point on ward we want them to reveal all the parties responsible and to give them the appropriate penalty. >> so the crisis has become a test of leadership not just for the kingdom of saudi arabia but also for the united states, which is something my next guest knows all about. retired four star general stanley mcchrystal led the u.s. forces in afghanistan and the coalition forces and also the anti-terrorism campaign in iraq before that. he taught a course on leadership at yale university and now he's written a new book about it called "leaders: myth and reality." and, stanley mcchrystal, welcome to the program. >> thanks for having me, christiane.

>> you know, it's really good to have you today. a lot of what we've been discussing on a geopolitical level and particularly now with the united states, you know, really implicated in this whole saudi/u.s. relationship, what to do about it. and i'm drawing on your expertise as a leader in the field and now you've written a lot about it. you have said the u.s. has to stand up and say khashoggi's murder is wrong. so what would you advise in a leading policy in that regard in answer to this? >> well, i think a long-term view is very important. one of the things i was reminded when i commanded in afghanistan is we had a 46-nation coalition. most of those other nations that came didn't come because they had interest in afghanistan. they came because they believed in the united states. they valued the relationship with us. it wasn't perfect but that was very important. so what i'd say when we look at the khashoggi issue, we do want to have a relationship long term with the king of saudi arabia

and we will. but it has to be based on trust. it has to be based on values. it has to be based on respect. were we not to show the strength in that now not to be demanding of our allies as we are of our enemies but also of ourselves long term, i think we pay a huge price. >> i want to see whether you agree with your former civilian boss, former defense secretary robert gates, who we keep pushing all these leaders as to what they think is the best response. as they call it, thread the needle, that you are talk bing about right now. he said this administration could do worse than look back at what the george h.w. bush administration did after the tiananmen massacre in china, beijing, in 1989. listen to what he said. >> he was the first head of state to impose sanctions on the chinese government to show how much we disapproved of what they

had done, but at the same time sent emissaries to the government to talk to the leadership in beijing, tell them why we were doing what we were doing, why we had to do what we were doing, but that we wanted to keep the strategic relationship still on track. >> so there are methods, right? i mean, this administration could just look back into the not too distant history book. >> well, i think so, and i completely agree with secretary gates. you have to tell them there is a future, but at the other time, you have to tell in there have to be levels of trust and values involved here, or in the near term, there's got to be huge consequences for that. >> i want to ask you to just put your hat on and look at it from the saudi point of view, again, with regards to leadership and what makes good leadership. so we read that for decades and decades the saudi royal family, the mosques, whatever you can call it, civil society or not,

nonetheless, the population ruled by consensus to try to keep the peace. and by and large, by and large, did. this particular new crown prince has vacuumed up so much power and is all concentrated in one person's hands, by and large, that this kind of thing may be allowed to go on. i guess i'm trying to ask you what you make of that kind of power dynamic in terms of leadership. >> well, often we confuse power and leadership. you can have an awful lot of power and you can exercise it through coercion or give rewards or things like that. it's not really leadership in my view because leadership is something that makes people better. leaders are people who pull us to higher values. they make us braver. they make us stronger. they make us more compassionate. they make us the things that we in our lives sometimes just don't do. so the temptation is to have political power or military

power or economic power, but the long-term thing that makes a difference is changing how people think, changing the values they exhibit on a daily basis. i think the saudis have taken a near-term view here and will also pay a huge price for that. >> president trump does tend to praise strong men, and i use that -- it's not gender neutral. it's strong men. he likes that. he doesn't actually like strong women like angela merkel but he does like strong men. to the point he was hinting that he wasn't satisfied with the saudi response to the killing of jamal khashoggi nonetheless said the saudi crown prince was in control and a strong leader. >> that's certainly what we've seen. i spent the last two years studying and writing a book on leadership, and the big conclusion for me after all this time of thinking about it was that leadership isn't what we

think it is, and it never has been. when we look back at leaders, we see leaders who grab on to either power or celebrity or zealotry or even their own personal genius and they confuse that for being real leaders. being real leaders means you got an interaction, a relationship with your followers that makes both better. it makes the leader better. it makes the followers better. and it constantly adapts to the situation. so if we think of leadership or power as this two-dimensional hammer that we pound on people until we get it, i think we really get a bad outcome. >> i'm going to get to some of the specifics in your book in a moment, but i want to ask you about the concept of dissent. because whether it's within a political context, within a military context, and what it actually means. how do you -- where do you come down on the concept of dissent? i mean, we have to sort of throw back to your sort of running against some kind of dissent.

you were forced to retire because of words you used, words your subordinates used, that got back to your civilian boss, and that was the president of the united states and he said, huh-uh, not dealing with you, general, you know. so where does dissent play? >> yeah. i think dissent is incredibly important on two levels. on a personal level as you get more senior powerful, you become a four-star general, there's a tendency for people to laugh at your jokes, tell you how smart you are, underwrite what you say because it's the dynamic. you wear your rank on your uniform. the danger with that is you start to believe you are smart, you are humorous, you are all of these things and your courses of action are right. you really need dissent around you that says, hey, guess what, stan, you got this completely wrong, and you have to construct people around you that did that for you. you know, i got married. that's worked in my personal life for many years.

but in a professional sense, you have to do that thoughtfully. you have to create it. on a national level, dissent has to be welcomed and celebrated. if somebody stands up and says, no, i think we got it completely wrong and here's my reason, if we criticize, if we stomp it down, not only do we lose that particular message which may or may not be right, but we cause a lot of other people to be more hesitant to dissent. there's always a certain group of people if they see someone else get attacked or publicly shamed or embarrassed, they won't raise their hand. and suddenly what we have is a quieting of the population. we start to create sheep. a nation of sheep is a dangerous place. that's not the american tradition. it's not what we want. we want a vigorous national debate, but it's got to be by people who are respected and respectfulful. >> okay. that raises a couple of questions. first the idea of not tolerating dissent is what got jamal

khashoggi killed. he was a reformist. he believed in the crown prince's reform but he blooe believed there should be a bigger consensus and bigger debate and believed the power was being too concentrated. what about the united states? do you believe the united states in the trump era is a nation of sheep? do you believe congress is a gaggle or a pack or whatever eep are in the plural? do you believe that if the military, the uniformed military of the united states is given an order that they not believe is a legal order? should they refuse it? >> well, for the military, i sort of take that off the table. i'm not on active duty anymore. if they get an order that is illegal, they absolutely are required not to follow it. i think that's separate. i think our political leaders, some of our social leaders, i think a lot have been quieted. i have a lot of conversations with people who have misgivings

but they say, you know, but the economy is doing well or, but, we got this that we like. we got that that we like. the danger is as we attack the media or attack our political opponents or put names that is publicly shaming or embarrassing to people, we start to over time cause people to be more and more reticent to say anything. if i know after teaching, i've been teaching almost nine years now, if a student asks a question or makes a constructive criticism in the class and slap them down with a smart response, i may feel good for that moment, but i lower the likelihood any other student is going to say anything. much of what might be very valuable. >> let's quickly go back over your recent military history. you were in iraq. you did catch al zawahiri, the leader of the al qaeda iteration in iraq.

that was a success. then you led troops in afghanistan and, frankly, it's currently not a success. afghanistan is the longest war, we've seen the highest number of civilians being killed there in a long, long, long time. we see the afghans even making the killings of their own forces a secret. like a national security secret. what is going wrong? this is a lot of money, nearly a trillion dollars, so many thousands of troops, so much death, so much injury. >> yeah, and, christiane, you've been there. i know there's a tendency to paint with a broad brush from afar and see afghanistan as a violent place with warlords and the taliban and corrupt officials and that's not untrue. but if you get close, you see an unprecedented number of females in school now for 17 years, ever

since 9/11. you see a new generation rising. it is not perfect. it's not even on getting to perfect in my lifetime or my son's lifetime. what it is, it's an effort by part of that population to have a better future. now, if we made a strict business case, i could say we should walk away from afghanistan, sort of wipe our hands of it and say that's money wasted. that might be true and it might be lies. i don't think that. i think when we make an effort to give people hope, when we give people opportunity, when we try to communicate around the world that getting stability and getting opportunity for people in an area like this, i think it's an investment that over the very long term pays off. i think the united states has actually been using, living off some of the things that were done for decades before now that built up a level of confidence and goodwill in our nation. so there is no easy answer in afghanistan, and i wouldn't be arguing to put a lot more troops or do anything like that, but i think a partnership with the

people of afghanistan and clear communication that we're involved in the region because we care does make a difference. >> i want to get back to your book because you have profiled 11 leaders, the vast majority of them are men, and you profile maybe three women. you talk about people like walt disney, al zawahiri, harriet tubman and robert e. lee. you also say that you realize there are just not enough women, you know, in your book and not enough women. you said it's unhealthy as well as, well, sort of immoral, whatever the right word is that you used. why? >> well, because women have traditionally been underrepresented in leadership positions. we have an interesting finding. it wasn't surprising to find out there were more male ceos in america than female ceos. it was surprising to find that there are more male ceos named

john than there are all female ceos. so there just haven't been the avenues. margaret thatcher, coca chanel, all different nationalities. completely different backgrounds. and all had a very tough road to leadership. the grocer's daughter, margaret thatcher, sort of works her way through a complicated british political system to become the most famous prime minister outside of winston churchill. she has a whole era named after her. harriet tubman, former slave, goes back 13 times to rescue other slaves. she's not a particularly outgoing woman. she speaks but she speaks for a larger cause. she's got this extraordinary ability to become a symbol for

others, not just females but also for african-americans and for everyone. then of course, coca chanel comes out of an orphanage and found an empire and does it by making people want to be like coco chanel and others to want to work for her. >> i never thought i would be talking about coco chanel with general mcchrystal when we met in afghanistan. nonetheless, it's very refreshing. can i just end with something? your own personal epiphany or road to damascus. for a long time general robert e. lee was your hero and you describe the great hero winston churchill as praising him as one of the best battlefield commanders and at the age of 63, you decided to ditch that. why did it take you so long? >> you know, i think it takes all of us a long time. i admired lee, the general, for all of those sort of traits that you have, honesty, courage, decisiveness on the battlefield, and i was encouraged to do that.

in my youth, i went to washington lee high school. i went to lees college, west point. then what happened is after charlottesville, i realized that lee's persona off shown in paintings or statues had been hijacked. it was being used by a part of america with white supremacist and other views to send a message i don't associate myself with. >> why? >> so i stepped away. i don't think he's horrible but i think we have to have a mature view. >> and that, too, is leadership, knowing when to step away. general mcchrystal, thank you so much, indeed, for joining us. and now we turn to a conversation with a great leader in the field of quantum physics, professor brian green is a world-renowned physicist and a bestselling author whose creative storytelling helps make complex scientific theories accessible to a general audience. he sat down with our walter isaacson to talk about the biggest scientific mysteries of

our time and how quantum computing could drastically alter our future. >> brian, welcome to the show. >> thank you. >> if you could solve three scientific problems, tell me what they'd be. >> very clear what they would be. so i want to know the origin of the universe. >> the origin of the universe. and we've gotten a little bit closer. >> we're closer. >> this past year. >> we're closer. but if you were to say to me, why did it start at all? we still don't have an answer to what happened at time zero. the origin of the universe, the origin of life. how did these particles coalesce and come together to yield living, breathing things like us? again, we're getting closer, but certainly we can't create life in the laboratory yet. we can do that, then i would say that we've really cracked that problem. and the third is the origin of mind, origin of consciousness. as you were talking about. how is it that particles that don't seem to think on their own, electrons and corks, do they cry? do they have emotions? i don't think so. somehow they all swirl together

and here we are having an inner life that somehow lights up. what turns on the lights in there? i don't know. >> explain to me how quantum computing works. >> there actually are small quantum computers in existence. this is not just pie in the sky. the classical computer, the ones that we typically use, it goes step and step and step and step. everything is sequential and everything is definite. in the quantum world you can do all of these fuzzy calculations at the same time and have them coalesce into the answer that you're seeking, which means you can do the calculations far more quickly, do the analysis far more quickly, tackle problems that a classical computer couldn't touch. >> what would that mean for our lives? >> to me, the real possibilities of quantum computing are to undertake problems that today we simply couldn't even approach using classical ideas or which we will take to a spectacular new level. one that comes to mind is

machine learning. so machine learning has the capacity to transform everything. we're used to having devices, be it a bulldozer or a jackhammer, that extends the power of the human form to do things that otherwise would be impossible, but that's just sort of a stronger, faster, leaner version of ourselves, if you would. it doesn't really replace creativity and the human intellect. machine learning many people suspect may be able to do that. when a machine can actually look at large data sets and not be told how to analyze them but learn by seeing the patterns, that's what we do. we are pattern recognition machines. and when a computer can do that, then burn a completely different arena, and that we see starting to happen and quantum computing is a very powerful means for recognizing patterns, dealing with large data sets. so this is at least decades off.

but this could be a place where we begin to really see computers doing the things that for the most part, for all of human history, we have viewed as intrinsically us. >> and that includes creativity, you said. >> i think so. >> it seems to me creativity means something a computer couldn't do which is thinking outside of a rule. tell me why. >> we like to say that because we like to think we're special. i don't mind the human species being a special entity. in reality. the fact of the matter is creativity may well be seeing unusual and hidden patterns within data, manipulating those patterns to a powerful effect. and that happens inside this thing inside our heads, this gray, gloppy thing and i think it operates by the rules of physics. if it operates by the rules of physics and doesn't have any other kind of inspiration, why can't a device outside of a gray gloppy thing inside of our heads also undertake those very same

kinds of calculations, computations and analyses? i think it's possible one day there will be somebody in that chair who's able to carry out this kind of interview we're having and certainly somebody who will do a better job than i am right here, and that is when we cross a threshold into a brave new world. >> that gray gloppy thing you referred to, it has consciousness. is consciousness explainable by physics? >> i think so. i don't have any proof of that. now we're in the territory of gut feel at the moment, but, again, i don't think there's anything going on inside our heads that isn't ultimately the motion of particles and the oscillation of fields and we have equations that describe those processes. they may not be the final equation. up day, perhaps, we will have them. i don't think you need anything else but physical law to describe ultimately what's happening inside of our heads.

and from that point of view, consciousness would simply be a quality of the physical world when there's a certain kind of collection of particles that come together in the right way and perform the right operations. >> you've been working, whether it be string theory and other things, on trying to capture what einstein wanted to do, which is a unified theory that would connect quantum to graphation to relativity and everything else. if we had a unified theory, wouldn't it all fit together again and not everything would be probabilities? >> well, if you believe albert einstein's vision, then, indeed, that's where we would be heading. einstein thought that if we could just get a unified theory, all of this quantum stuff that was certainly working, described in the data. he couldn't deny that, but he thought it's just a steppingstone to the deeper understanding and when we get there, no more talk of probabilities. no more talk of entanglement. no spooky action. that's what he thought.

but, you know, he passed on a while ago, right, 1955. in the half century since, every single piece of experimental data, every single math mall development has pointed away from that vision. the vision that we have now is that the quantum world is here to stay and just accept it and get on with it because having that old vision is coming from an intuition that was built up over a long course of human history but it's the wrong intuition. >> so you don't think there's a unified theory. >> i do think there's a unified theory. i don't think it will accomplish what ion steen hoped it would. >> in other words, we'll still have certainty. >> we'll have uncertainty, all this weird quantum stuff will still be with us. the advantage of the unified theory is finally we'll put together our understanding of gravity and understanding of quantum physics into one unified whole. that would be progress. i don't think the progress will wipe out the quantum understanding. >> the other great advance in

the past couple years was cosmic background radiation came along. what is that? explain to us. >> is the cosmic microwave radiation is our most powerful insight into cosmology. we want to know how the universe began. with einstein's general theory of relatively, updated by more sophisticated versions of the cosmology it gives rise to in recent years, we have a pretty good sense. in the early universe we believed there was a kind of gravity that drove everything apart, rapidly stretched the fabric of space. and when we do our calculations that stretching would also stretch out little tiny quantum uncertainty in the early universe, sort of like if you have a piece of spandex. when you stretch out the spandex you can begin to see the pattern itching of the fabric of space through the stretching, and that is the microwave background radiation. and we can do calculations that predict how the stitches should

look. tiny temperature variations across the night sky. and holy smokes, when we do the observations and compare it to the calculations, they're spot-on accurate. we're talking processes that happened 13.8 billion years ago. >> wait. 13.8 billion years ago, something happened and this wave came and finally hit us? >> that's right. when we look up in the night sky, see the microwave background photons, they've been traveling for 13 million years and the lights have just the properties that our mathematics predicts they should. we human beings crawling around on this political planet 13.8 billion years late remember able to develop equations that give us insight into processes that happened billions of years ago. >> so what does that tell us about how the universe began? >> it probably began as this compressed, tiny nugget that was filled with an exotic cosmic fuel. the name doesn't matter much. but it's a fuel that gives rise to an exotic kind of gravity. this repulsive gravity, that

pushes everything apart. that's the bang and the big bang, and we've been living through the aftermath of that cosmic explosion ever since. and the only reason why we believe these ideas is because of the microwave background radiation so completely agreeing with what our predictions say it should look like. >> the cosmic background radiation helps understand what happens in black holes. that's been one of your fascinations which is the edge of black holes. let me ask you about the edge of time, how you try to explain that through art, through i think these ideas need to be widely understood, widely discussed, widely shared. and so if they stay within the hallowed halls of universities or esoteric journals, it doesn't get out there. we've tried various unusual blendings of science and art to try to reach a broader audience. this piece you're referring to, i collaborated with phillip glass. i wrote a short story, a

rewriting of the myth of icarus. boy doesn't go near the sun with wax wings. he builds a ship and flies near the edge of a black hole. near the edge of a black hole, time slows down. when he comes back, thousands of years have gone by on earth but only a couple hours for him. so his dad is gone, his family is gone. it's a traumatic story. philip liked it and we turned it into a live stage work, where there's an orchestra, a film, and a narrator that takes the audience to the edge of the black hole. >> we're navigating to avoid an uncharted black hole. >> a black hole. cool! >> and when you have that kind of experience, it doesn't just make your head hurt, it kind of makes your heart pound, right? if you get into the story you can feel the chill of the experience. let me tell you one thing, my son when he first encountered the stories i wrote, at the end, he was crying. someone said, don't you feel bad? you wrote a story that made your son cry because the dad is dead. i said, to. if general relatively which is

ultimately in this story can make a 5-year-old cry, it's a good thing. that kid is feeling the science. you need to feel these ideas in order that they aren't just esoteric abstract nonsense. >> so much of this stuff is not something we can apply in our daily lives. we'll never go near the edge of a black hole. we're never going to travel near the speed of light. why is it important that we understand it? >> well, my own sense is that the universe is incredibly rich and you don't have to know these ideas to live in this world. my mother doesn't know these ideas. she says they give her a headache, and i totally get that and i respect it. but if you can get these ideas, it opens up a reality in wondrous ways. to walk down the street and think time for you is elapsing at a different rate from somebody on a street bench. right? to look up into the night sky and think about the quantum processes that do give the microwave background radiation,

to think about quantum physics allowing us to tunnel through barriers or have these strange, spooky connections. it's just wondrous. and how tragic if people are cut off from these ideas simply because they don't speak the technical language of mathematics and physics. that's why the ideas need to be brought out to the world in many various ways. >> explain to me, though, that notion of you walking down the street and you're saying to yourself, time is traveling for me differently than a person moving in another direction. >> yeah, well, i tried to see what it would be like to live these ideas. so at times i've forced myself to go around the world and really imagine in detail what's going on. with time and with space and quantum physics. yeah, one of the key ideas of relativity is when you move, relative to somebody else, your clock is ticking off time at a different rate. and it's very hard to hold these ideas in mind because you are

assaulted all the time by conventional reality telling you that all clocks tick off at the same rate, which is wrong. it's false. but it's hard to live with the truth because so much of your experience contradicts it. it's counterintuitive because these effects are very small in everyday life. i find there's something deeply wondrous every so often in actually living these ideas. >> if i walk down broadway today, what am i supposed to observe and watch? >> first of all, recognize the sidewalk is mostly empty space and you're actually not touching the sidewalk because it's actually the electrons in your shoes that are repelling against the electrons in the concrete, so you're floating as you're walking along broadway. yeah, your time is elapsing at a different rate than someone who is sitting relative to your motion. your time is elapsing faster than a person at the top of the

empire state building. your watch is going slower than theirs. >> why is that? >> the answer comes from einstein's theories. i can imagine a world where that isn't the case. it's not like i can say logically, it had to be that way. einstein s einstein's general relativity. gravity doesn't just pull on matter. it pulls on time. when it pulls on time, it makes time elapse more slowly. at the surface of the earth, our gravity is a little stronger, the pull is stronger. time goes slower than at the top of the empire state building. yeah. it's crazy. >> i agree. thank you. pleasure. >> is while my time may, indeed, be elapsing in a different rate than yours, that is still all the time we have because that's it for our program tonight. thanks for watching "amanpour and company" on pbs, and join us again tomorrow night. uniworld is a proud sponsor of "amanpour and company."

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♪ - this week on milk street, we finally uncover the secrets to great homemade pizza dough. then we make a very simple shaved zucchini salad. and, finally, we travel to rome to uncover the secrets of the mother of all pasta sauces. that would be cacio e pepe, cheese and pepper. stay tuned for the roman classics right here on milk street. - funding for this series was provided by the following.