TOWARDS A WORLD WITHOUT WARS
by Joseph Rotblat
Former President, Pugwash Conference on Science and World Affairs, and
Nobel Peace Prize Laureate, 1995
This lecture will be mainly about humankind and science, which is part of humankind. And since I am a scientist, I'll talk a little bit about myself.
Humanity, An Endangered Species
I am a man of peace. Of course, you would expect this of a person who has been awarded the Nobel Peace Prize, but that doesn't necessarily follow. I am also a pacifist. I abhor war. I dislike immensely any violence. But I am not an absolute pacifist. I describe myself as something like a realistic pacifist, though that may sound like an oxymoron. I am not an absolute pacifist, because I do not believe in absolutes. Nature is so immensely rich with infinite variety of possibilities that nothing can be excluded. By the same token, nothing should be impossible. Any concept that seems out of this world can be realized if enough faith and effort are put into it. A world without war is such a concept. The theme of my lecture is to indicate to you that this is a necessary condition for the survival of humankind on this planet.
You may have different views about the origin of the human species. You may take the view of the Judeo-Christian Bible that it is the deed of God on the sixth day of creation. Or you may take the other extreme, the view of the rationalists who say that human life is the result of an infinite number of seemingly random changes in the molecular structure of some parts of the body. But whatever view you take, I'm sure you will agree that life is our most precious commodity. We cannot imagine that the whole species can come to an end, least of all by the action of man. Yet, the unimaginable has now become possible.
The continuation of the human species on earth can no longer be guaranteed. The human species is now an endangered species. Of course, one always envisions that human life may come to an end. But we always think of it as the result of some cosmological event, say a collision with a meteorite or with a comet or perhaps a violent volcanic eruption. Indeed, we believe that some types of animals that once dominated this planet, like the dinosaurs, became extinct as the result of some such event, although we don't exactly know the nature of that event. Because that event took place 65 million years ago and nothing of that magnitude has occurred since, you may say that for all practical purposes, we can forget about it.
That human life could come to an end by the action of man was never considered seriously. Of course, throughout history we have had wars with terrible carnage. Despite the fact that the 20th century is supposed to be an enlightened century, in absolute terms, the largest number of fatalities in war have occurred in this century. In the First World War, 8.5 million people perished as the direct result of combat. In the Second World War, 55 million people died. And since the end of the Second World War, between 20 million and 40 million people have been killed in various wars, mainly in the developing countries.
Perhaps the worst case of genocide occurred during the Second World War when, under the orders of Hitler, a systematic, almost a scientific program of extermination was carried out on people for no reason other than that they were members of a certain race. In all these atrocities, however, the human species as such was not endangered, largely for technical reasons.
Now, however, these technical obstacles have been overcome. Omnicidal weapons have been introduced, the weapons that destroyed Hiroshima and Nagasaki. The destruction of these cities heralded a new age, the Nuclear Age. The chief characteristic of this age is that for the first time it has become possible for man to bring the whole human species to an end in a single act.
Now, I wouldn't be surprised if some of you think that I am exaggerating. I wouldn't be surprised because I myself, although involved in the making of these weapons, did not believe it either. When we started the atom bomb project in England in 19391940, which was well before the Manhattan Project in the United States, we already had a good idea of the enormous destructive power of the bomb. We knew all about the blast effect. We knew about the heat wave. We also knew about the radioactive fallout. But even so, we did not believe that the atom bomb could bring about the end of the human race. For that, we calculated, one would need a very large number of nuclear weapons, something of the order of 100,000 of them. And even in our most pessimistic scenarios, we could not imagine that human society would be so stupid as to accumulate this obscenely huge number of weapons for which we could see no purpose whatsoever. And yet, it turns out that human society was that stupid.
Until a very short time ago, this huge number of nuclear warheads, a hundred thousand of them, were accumulated mainly in the arsenals of the two great powers of the time, the United States and the Soviet Union. And on several occasions we came very close to their actual use.
I remember one such an occasion in particular-the Cuban missile crisis of 1962, when we were a hair's breadth away from the ultimate catastrophe. It all depended on the decision of one man. Fortunately, Nikita Khrushchev was a sane man. But we may not be so lucky next time.
"Here then is the problem which we present to you, stark and dreadful and inescapable. Shall we put an end to the human race or shall mankind renounce war?"
Forty-two years ago, a number of scientists who realized the great danger to humanity issued a manifesto known as the Russell-Einstein Manifesto. The first part of this manifesto said: "We are speaking on this occasion not as members of this or that nation, continent, or creed, but as human beings, members of the species man, whose continued existence is in doubt." Then it went on: "Here then is the problem which we present to you, stark and dreadful and inescapable. Shall we put an end to the human race or shall mankind renounce war?"
This manifesto was signed by 11 scientists, starting with Bertrand Russell and Albert Einstein. I am now the only surviving signatory of that manifesto, and as such I feel it my duty, even my mission, to keep on posing to the world this question: "Shall we put an end to the human race or shall mankind renounce war?"
Men of Peace, Leading the Arms Race
With the end of the Cold War, the immediate danger has abated. We are now in the process of reducing the nuclear arsenals. We still don't see any signs of willingness of the five nuclear-weapons states to go ahead with their elimination, although they are committed to this. Therefore, nuclear weapons are still here. And as long as they are here, there's always the danger they may be used. But, as I said, the immediate danger is now somewhat less. However, other means of mass destruction may be invented, other means perhaps even more readily available than nuclear weapons.
Here again, you may wonder why scientists should engage in activities that may bring the human race to an end. Going back to nuclear weapons, I have to remind you that the atom bomb was the invention of scientists who started the work on their own volition. Nobody compelled them to do this. Most of them were people with a humanistic approach to science. But how did they come to engage in such activities?
Perhaps the best way to answer this is to use a specific example, and here I'm using myself as this example. From my youth I was a great enthusiast of science. I believed that science has a purpose, that it should serve mankind and improve the lot of people, certainly not cause destruction. So how did it come about that I, on my own volition, in 1939 when I was in Liverpool, went to the head of the department, James Chadwick, who discovered the neutron, and suggested to him that we should start work on the atom bomb?
The answer to this question lies partially in a coincidence, a quirk of history, namely, that the breakthrough discovery that led to the atom bomb was made shortly before the Second World War. This vital discovery was the discovery of fission, which was made by two Austrian scientists, Lise Meitner and Otto Frisch, following some work of German chemists. The discovery was that if you hit the nucleus of a uranium atom with neutrons, an elementary particle, it may break into two almost equal halves, for example, into the atoms of krypton and barium. In this process, a relatively large amount of energy is released.
Now this paper by Frisch and Meitner was published in February 1939. As it happens, at that time, I was doing some experiments using uranium and neutrons. It occurred to me that in this process, apart from producing these two fragments, some more neutrons may also be emitted. The process may be something like this. You hit the uranium atom; you produce these two types of atoms and also a few neutrons as well. It didn't take more that a few days to carry out the experiments that confirmed that, indeed, several neutrons were coming out at this process of fission. Let me add very quickly that this same discovery was made independently and simultaneously in several other laboratories. This is how science works. When an idea is ripe, it occurs to many scientists.
What is the importance of this observation? The importance is that you can start a nuclear chain reaction. If you take some of the neutrons that are emitted here, you can use them to hit other uranium nuclei to produce more fission and more neutrons and so on. It'll go on and very quickly, in an exponential fashion, a very large amount of energy is released. This was the first time it became possible to utilize the vast stores of energy contained in the atomic nucleus. And this is the energy that you are now using. About one-fifth of all our electricity in this country (U.K.) comes from this source, nuclear reactors.
Out of this, another idea emerged, namely, that if this multiplication of neutrons in the fission process occurs in a very short time-and my calculations have shown it would occur in less than a microsecond, less than a millionth of a second-you then get a mighty explosion, in other words, the atom bomb. So the idea of the atom bomb had already occurred to me and to other scientists in early 1939.
As soon as I had this idea, I tried to push it out of my mind. The notion that I should be involved in making a bomb, a weapon of mass destruction, was completely contrary to everything I held true about science. So I tried to forget about it. Nevertheless, I had this feeling that other scientists might not have the same moral scruples. In particular, I had in mind the scientists in Germany, where some of the work had started. I was afraid that if German scientists under Hitler pursued the idea and made a bomb, then it was likely that Hitler would win the war and Nazism would then conquer the world. I could not accept this. This was a terrible time for me, perhaps about the worst dilemma that a scientist could experience. On the one hand, working on a tool of mass destruction went against all my ideas of science. On the other hand, these very ideas were in danger of being eradicated if Hitler acquired the bomb and the war was lost.
Nuclear Deterrence, A Flawed Principle
It took me the whole summer of 1939 to fight with myself about this, and eventually an external event made up my mind for me. That event was the start of the Second World War when Germany invaded my native country, Poland. Within a few weeks, the German army overran Poland, and the whole military might of Germany was exposed. It became clear to me that if, in addition, Hitler had the bomb, then he would no doubt use it and the whole of our world, science, and humanity would be lost. And this I could not accept.
So this is the reason why I went to Chadwick and suggested that we start work on the atom bomb. I subsequently have found that many other scientists started the work for the same reasons. I did not abandon my humanitarian principles. On the contrary, I used these principles as a reason for starting the work. I reasoned that if the bomb could be made, then the only way to prevent Hitler from using his bomb against us would be to have a bomb ourselves with which to threaten retaliation. This is, in other words, the concept of nuclear deterrence, which is used to this day as a reason for retaining nuclear weapons. And as I've said, other scientists used the same sort of reasoning. We needed the bomb not to be used, not even against Germany, but to prevent its use by the Germans. So, we had to act quickly before the German scientists could succeed.
As it turned out, this fear was unfounded. The Germans did start their atom bomb research at the same time we did, but due to some wrong calculations and faulty experiments, they came to the conclusion that it wouldn't work. They thought such a device would weigh a ton or more and that in any case they couldn't get enough material for it. So they gave up the atom bomb project in 1942, even before the Manhattan Project in the United States started in earnest. But, of course, we didn't know about this until much later.
Later on, I realized that this concept of nuclear deterrence is flawed for various reasons. One reason, for example, is that deterrence will only work if your opponent is a reasonable person. It will not work with an unreasonable person. And as we know from history, often we do get national leaders who behave irrationally. And indeed, even if they are rational leaders, they may begin to behave irrationally in case of war, particularly if they face defeat. I'm convinced, although I cannot give you any proof for it, that if Hitler had had the bomb, his last order from the bunker in Berlin in April 1945 would have been to drop the bomb on London, even if it meant terrible retribution to Germany. It would have been in line with his philosophy of Götterdammerung, the "Twilight of the Gods."