During all this time of inner turmoil, he preserved his outward calm, so that none of his friends knew that he was going through a profound crisis, evidence of his remarkable inner strength. There was only one incident in which his calm exterior cracked open, to reveal a man under a severe strain. This was in August 1948, when he was beginning to be troubled by doubts, and was already cutting back his espionage activities for Russia. He was attending a meeting of several atomic scientists at the General Electric Company in London. He did not have his car, and when another Harwell scientist, S. M. Duke, offered him a lift back after the meeting, Fuchs accepted. As they were driving along, a hard object suddenly smashed against the windscreen, shattering it. Duke, with considerable presence of mind, knocked out the windscreen with one hand so that he could see through, and at the same time braked hard. Fuchs was thrown on to the floor.
He appeared to be terrified. Duke called the Automobile Association, and Fuchs refused to leave the car until they arrived. No one could work out what had shattered the windscreen; the AA man said it could have been a lead pellet from a boy’s catapult, or a ricocheting bullet from a hunter’s rifle somewhere nearby. But Fuchs seemed to think that it was a deliberate attack, although no one could have known that he would be travelling in this car, and there were no other cars nearby. Evidently, his mind was invaded now by vague fears of retribution, either for spying for Russia, or for becoming less enthusiastic about doing so.
Fuchs’s father Emil came on another visit, on his way back to Germany from a Quaker Centre in Pennsylvania, and this time he brought his grandson, Klaus, with him, the son of his daughter Elizabeth, who had committed suicide. They both stayed with the Skinners. Again, Emil Fuchs was popular at Harwell during his stay. He was invited to parties and he went, and unlike his son he would join in the singing merrily. He had an air of cheerful calm. One evening at the Skinners’, when everyone was rushing around getting ready for a party, he sat in the midst of the bustle typing out a lecture on the fellowship of Jesus.
His grandson Klaus was then twelve, and he showed the nervous greediness of a boy brought up in a country of deprivation. When they were asked out to tea and a plate of thin sandwiches was put in front of him, he wolfed down the lot, glancing around nervously as he did so.
It was clearly going to be difficult for Emil Fuchs, who was then seventy-five, to continue to raise his grandson. Fuchs suggested that he bring the boy to England and adopt him. He talked to the Peierls enthusiastically about the idea, which they did not discourage, and about buying clothes for the boy.
On 23 September 1949 a startling announcement came simultaneously from the White House and 10 Downing Street. It said: ‘We have evidence that in recent weeks, an atomic explosion occurred in the USSR.’
In retrospect, it is obvious that the West could not be for long the sole possessors of this uniquely devastating weapon, but at the time this was a shock. As the New York Times said in an editorial the following day: ‘We are prepared for the event intellectually, but not emotionally.’ Certainly few people expected the Soviet Union to complete an atomic bomb so soon. The best estimate given to the US State Department in the spring of that year, which was not made public, was that it would be at least two years before Russia exploded an atomic bomb, and probably much more.
Harwell scientists were as surprised as everyone else. The announcement came on a Saturday, and several senior people hurried over to the Skinners’ house to talk about it, including Cockcroft. Fuchs was sitting in the centre of the room, his legs crossed, as usual, his phlegmatic manner contrasting with the agitated features of most of the others. Everyone was speculating about how the Russians did it. Skinner said they must have been helped by some kind of leak of information from the West. Fuchs disagreed: he said the Russians could have found a short-cut, so that they did not have to go through all the stages that British and American scientists went through. Privately, he was as surprised as the others that the Soviet Union had achieved this so soon. He had underestimated not their scientists, but their industrial capability. But this was a thought he kept to himself, as, also, whatever thoughts he had about his own contribution to the Soviet achievement.
The following month, Emil Fuchs wrote to his son to say that he had been offered the post of Professor of Theology at the University of Leipzig, and he had accepted. This was in what was then the Soviet occupation zone, and was soon to become the German Democratic Republic. Fuchs knew that his father disapproved of many things the Communists were doing, but also that he disliked what he saw as the selfish materialism and incipient militarism of the new Germany that was already arising in the Western occupation zones. He felt that the Communists were at least trying to build a better society than that, and believed he could usefully criticize their system from inside. Much of this he told his son in letters, and most of it accorded with Fuchs’s own feelings.
Fuchs did something that people often do in times of stress, and transferred his anxiety. He was worried about his own activities, but he transferred this worry to his father’s. He went to Henry Arnold, the security officer and his friend, with this. There could be a security problem because his father was moving to the Soviet zone, he said. Should he resign from Harwell? Arnold mulled this over and said the question of whether or not he should resign was one for the administrative authorities. However, he said, Fuchs might think about what he would do if the Russians put pressure on him through his father. Fuchs said he did not know; he might do different things in different circumstances.
Fuchs was drawn to Arnold, as to a father confessor. It was as if, simply by having Arnold’s approval as a friend, the approval of the security officer, he was being forgiven for the crimes against security that he had committed. But also, it was half-way to confessing, and there were times when he felt like telling Arnold everything.
Arnold sensed that there was an element of gameplaying in their friendship, that Fuchs was drawn towards confessing something. He had cultivated Fuchs’s friendship deliberately, but he was not the kind of man who can sit back coldly and manipulate someone else’s feelings. To some degree at least, the friendship was genuine on his part, although he would on occasions deny it. In a conversation years later, he struggled to explain his feeling for Fuchs. ‘I can’t call him a friend exactly, but I had affection for him… Well, was it affection? More than friendship, I felt sorry for him, because I knew for a long time how it had to end.’
Fuchs told Arnold he wanted to talk to him again about his father’s move, but he had nothing new to say, and he asked him again whether he would have to leave Harwell. The idea was becoming fixed in his mind that he would have to leave the place he loved. This was supposedly because of his father’s position, but there was also the thought somewhere in his mind that it would be in expiation of his own offences against Harwell. He told Arnold it would be easy for him to find a university post, but he did not make any move to do so.
What Fuchs did not know was that the security authorities were aware of his father’s move as soon as he was, because his mail was being intercepted and read and his telephone was being tapped. He was under suspicion.