He did not contact any of his former friends in Britain or America. He wrote once to a former colleague at Harwell who was junior to him, Brian Flowers (now Lord Flowers), inviting him to a scientific conference he was organizing. It was a formal letter that did not acknowledge in any way that they had been acquainted: he addressed Flowers, whom he had always known as ‘Brian’, as ‘Dr Flowers’. Flowers wrote back a brief letter addressed to ‘Dear Klaus’ and turning down the invitation. However, Fuchs did write to Gordon Hawkins, the assistant governor of Wakefield Prison, telling him: ‘The conversations I had with you — in particular the philosophical ones — belong to the pleasant memories of my time at Wakefield.’
(Odd that he should have pleasant memories of Wakefield gaol.)
Soon after Fuchs went to East Germany, Nicholas Kurd found himself in West Berlin. He noticed that there was a conference in East Berlin which he thought Fuchs would probably be attending, ascertained that he would be there, and telephoned him; Fuchs suggested lunch, and Kurd crossed the Wall to meet him.
Fuchs told him over lunch that he was upset by the attitude of his friends in England; he thought they might have been more sympathetic. He said he knew how they felt, he understood that what he had done was wrong from their points of view, but there were mitigating circumstances, and they might have been more understanding of his point of view. He said the one person who had remained a good friend throughout his difficult times was Henry Arnold, and he asked to be remembered to him.
They touched on politics only once. Kurd said he had been reading the East German newspapers, and found them so narrowly one-sided in their view of events that they made the British Communist Party newspaper, the Daily Worker, seem like an organ of liberal opinion by comparison. Fuchs laughed at this and nodded sympathetically, but said that the Government in East Germany was trying to change society, and this was not easy.
The Director of the Institute for Nuclear Research was Heinz Barwich, a German physicist with pro-Soviet sympathies who had gone to the Soviet Union after the war and worked on the Soviet atomic bomb programme, and earned a Stalin Prize. At the Institute, Barwich had his difficulties with the Communist Party. A party bureaucrat was installed at the Institute and interfered with the way it was run, until Barwich found the situation intolerable and demanded his removal; after a struggle, he got it. When he learned that Fuchs was to join the Institute as his deputy, he looked forward to having at his side a man who, as he saw it, had already shown great moral courage and independence. He assumed that Fuchs would be an ally in any future struggles with the bureaucracy. But he was disappointed; he found that Fuchs followed the Party line on everything dogmatically, and never differed from its dictates or its officials.
Barwich became disillusioned with Communism, and in 1964 he defected to the West while he was attending a scientific conference in Geneva. Later, he testified before a US congressional committee about the Soviet atomic bomb programme, and said that Fuchs, by his help, had probably saved the Russians two years’ work.
On Fuchs’s behaviour in East Germany, he recalled Fuchs’s self-analytical confession that was read out at his trial, and the passages about dividing his mind into two compartments. He said that as he saw it, Fuchs had evidently decided to put an end to the split in his personality, and deliver himself totally to the service of Communism.
Certainly Fuchs had become, in his public persona at least, a dogmatically faithful Communist, following the party line on every issue, a transformation wrought by some combination of political reconversion, self-delusion and perhaps opportunism, for he had to live in East Germany and pursue his career there. He occasionally gave interviews to the official media supporting the official Soviet line on some issue of the day concerning nuclear weapons. When the Soviet Union ended its moratorium on nuclear weapons testing in 1961, he told the East German news agency that this was a correct and necessary step. In his only interview with a British newspaper, the Daily Express, he accused West Germany of setting out to build an atomic bomb.
In August 1986, when the Soviet Union was pressing the United States to sign a nuclear test ban to include underground tests, he wrote an article in Neues Deutschland, the official Communist Party newspaper, appealing for a worldwide ban on nuclear tests. ‘The history of humanity cannot be allowed to end in an atomic inferno,’ he wrote. ‘I appeal to all men of goodwill who care about the future of our planet. Let us stand up for a ban on all nuclear weapons tests.’
He attended a colloquium held in East Berlin to mark the seventy-fifth anniversary of Max Planck’s first paper on quantum theory. He presented a paper on the philosophical implications of the theory, although largely to dismiss them, in strict Marxist materialist terms. Underlining his orthodoxy, he quoted Marx in his paper: ‘The question of whether human thought is capable of objective truth is not a question of theory but a practical question.’ And he quoted Lenin: ‘There is no abstract truth; truth is always concrete.’ Coincidentally, another paper at this colloquium was read by Bruno Pontecorvo, who defected from Harwell the year after Fuchs was arrested and was given a post at a nuclear research institute near Moscow.
Fuchs was honoured in East Germany both for his scientific and his political work, although no reference was ever made to his espionage on behalf of the Communist cause. He was elected to the German Democratic Republic’s Academy of Sciences, and also to the Communist Party Central Committee. He was awarded the Order of Merit of the Fatherland, and the Order of Karl Marx. On his seventieth birthday, the East German Communist leader, Erich Honneker, sent him a message saying: ‘You can look back on a successful career as a Communist, a scientist and a university teacher.’
When Victor Weisskopf went to East Germany to give some lectures, he told scientists he met there that he would like to see Fuchs. Weisskopf has been deeply concerned with the moral and political implications of the manufacture of nuclear weapons ever since Los Alamos, and has often been critical of American policies. Fuchs telephoned him and invited him to lunch at a smart restaurant.
They talked about politics. Weisskopf criticized the Soviet Union on a number of issues: civil rights, Afghanistan, the treatment of Jews. Fuchs defended the Soviet Union all the way, but as always he spoke quietly and without passion. He would say to Weisskopf, mildly, ‘No, I’m afraid you don’t understand the situation,’ or ‘I don’t think you’re right about that.’
Weisskopf raised the treatment of Andrei Sakharov, the dissident Soviet physicist, and Fuchs became unexpectedly vehement, although he still spoke quietly. ‘Sakharov is a traitor,’ he said. ‘He wants the United States to have more missiles than the Soviet Union. The Soviet authorities are treating him very well. These people deserve a harsher punishment.’
Fuchs’s father lived for many more years to enjoy his son’s success and prestige in his own country. He died in 1971, at the age of ninety-six. He wrote his autobiography, which was published in two slender volumes. He told an English friend that there was a third volume in manuscript form, which was to be published only after his death. ‘I am not altogether popular with the authorities,’ he explained with a twinkle. The manuscript has never been found.