In the course of this work I began naturally to form bonds of personal friendship and I had concerning them my inner thoughts. I used my Marxist philosophy to establish in my mind two separate compartments. One compartment in which I allowed myself to make friendships, to have personal relations, to help people and to be in all personal ways the kind of man I wanted to be and the kind of man which, in personal ways, I had been before with my friends in or near the Communist Party. I could be free and easy and happy with other people without fear of disclosing myself because I knew that the other compartment would step in if I approached the danger point. I could forget the other compartment and still rely on it. It appeared to me at the time that I had become a ‘free man’ because I had succeeded in the other compartment to establish myself completely independent of the surrounding forces of society. Looking back at it now the best way of expressing it seems to be to call it a controlled schizophrenia.
In the postwar period I began again to have my doubts about Russian policy. It is impossible to give definite incidents because now the control mechanism acted against me, also keeping away from me facts which I could not look in the face, but they did penetrate and eventually I came to a point when I knew I disapproved of a great many actions of the Russian Government and of the Communist Party, but I still believed that they would build a new world and that one day I would take part in it and that on that day I would also have to stand up and say to them that there are things which they are doing wrong. During this time I was not sure that I could give all the information that I had. However, it became more and more evident that the time when Russia would expand her influence over Europe was far away, and that, therefore, I had to decide for myself whether I could go on for many years to continue handing over information without being sure in my own mind whether I was doing right. I decided that I could not do so. I did not go to one rendezvous because I was ill at the time. I decided not to go to the following one.
Shortly afterwards my father told me that he might be going into the Eastern Zone of Germany. At that time my own mind was closer to his than it had ever been before, because he also believed that they are at least trying to build a new world. He disapproved of many things and he had always done so, but he knew that when he went there he would say so and he thought that in doing so he might help to make them realize that you cannot build a new world if you destroy some fundamental decencies in personal behaviour. I could not bring myself to stop my father from going there. However, it made me face at last some of the facts about myself. I felt that my father’s going to the Eastern Zone, that his letters, would touch me somewhere and that I was not sure whether I would not go back. I suppose I did not have the courage to fight it out for myself and, therefore, I invoked an outside influence by informing Security that my father was going to the Eastern Zone. A few months passed and I became more and more convinced that I had to leave Harwell. I was then confronted with the fact that there was evidence that I had given away information in New York. I was given the chance of admitting it and staying at Harwell, or of clearing out. I was not sure enough of myself to stay at Harwell and, therefore, I denied the allegations and decided that I would have to leave Harwell.
However, it then began to become clear to me that in leaving Harwell in those circumstances I would do two things. I would deal a grave blow to Harwell, to all the work which I had loved and, furthermore, that I would leave suspicions against people whom I loved who were my friends and who believed I was their friend. I had to face the fact that it had been possible for me in one half of my mind to be friendly with people, be close friends and at the same time to deceive them, to endanger them. I had to realize that the control mechanism had warned me of danger to myself, but that it had also prevented me from realizing what I was doing to people who were close to me. I then realized that the combination of the three ideas which had made me what I was, was wrong, in fact that every single one of them was wrong, that there are certain standards of moral behaviour which are in you and that you cannot disregard. That in your actions you must be clear in your own mind whether they are right or wrong. That you must be able, before accepting somebody else’s authority, to state your doubts and to try and resolve them; and I found at least I myself was made by circumstances.
I know that I cannot go back on that and I know that all I can do now is to try and repair the damage I have done. The first thing is to make sure that Harwell will suffer as little as possible and that I have to save for my friends as much as possible of that part that was good in my relations with them.
This thought is at present uppermost in my mind, and I find it difficult to concentrate on any other points. However, I realize that I will have to state the extent of the information that I have given and that I shall have to help as far as my conscience allows me in stopping other people who are still doing what I have done.
There is nobody I know by name who is concerned with collecting information for the Russian authorities. There are people whom I know by sight whom I trusted with my life and who trusted me with theirs and I do not know that I shall be able to do anything that might in the end give them away. They are not inside of the project, but they are the intermediaries between myself and the Russian Government.
At first I thought that all I would do would be to inform the Russian authorities that work upon the atom bomb was going on. They wished to have more details and I agreed to supply them. I concentrated at first mainly on the products of my own work, but in particular at Los Alamos I did what I consider to be the worst I have done, namely to give information about the principles of the design of the plutonium bomb. Later on at Harwell I began to sift it, but it is difficult to say exactly when and how I did it because it was a process which went up and down with my inner struggles. The last time I handed over information was in February or March, 1949.
Before I joined the project most of the English people with whom I had made personal contacts were left-wing, and affected, to some degree or other, by the same kind of philosophy. Since coming to Harwell I have met English people of all kinds, and I have come to see in many of them a deep-rooted firmness which enables them to lead a decent way of life. I do not know where this springs from and I don’t think they do, but it is there.
I have read this statement and to the best of my knowledge it is true.
Statement taken down in writing by me at the permission of Emil Julius Klaus Fuchs at the War Office on January 27, 1950. He read it through, made such alterations as he wished and initialled each and every page.
Acknowledgements
I am grateful to the following people for providing me with information about Klaus Fuchs or his background. They are listed here according to the place of their principal association with Fuchs, although in many cases they knew him at other stages of his career as well.
For convenience, I am leaving out the academic titles of ‘Doctor’ and ‘Professor’ since the majority of people on this list have them. A few other informants have preferred to remain anonymous.