Review of The Spy Who Changed the World by Mike Rossiter (Headline, 2014)

Klaus Fuchs was a German mathematician/physicist who fled Germany in 1933 to Britain.  There he found employment, first in Bristol University, then Edinburgh, before being interned at the start of the war as a German national and being sent to a camp in Canada.  He was then repatriated back to Britain, where he started to work on nuclear research.  As plans started on the Manhattan Project and the development of a nuclear bomb, Kuchs formed part of the British contingent, first moving to New York, then onto Los Alamos, where he was a key member of the theoretical physics team.  At the end of the war he returned to the UK to take up a post as a key member of Britain’s new nuclear programme. 

Fuchs was undoubtedly a leading nuclear scientist who made key contributions to the development of the nuclear age, but his infamy owes more to the fact that throughout his time working on nuclear physics in Britain and the United States he was passing on everything he knew about the programmes he participated in to the Soviets, enabling them to become the second state to possess nuclear weapons much earlier than expected.  In fact, Fuchs had been an active and politically committed communist his whole adult life and it was his activism against the Nazis that forced him underground, then out of Germany.  His spying only came to an end in 1950 when he confessed to his activities to British authorities, despite the quite thin evidence against him, under the impression that he would be able to continue his work for the British. 

Given the importance and scale of the material he passed on, Mike Rossiter claims Fuchs was the most significant spy of the twentieth century, and The Spy Who Changed The World tells Fuchs story drawing on declassified archive material in Britain, Germany and Russia.  It’s a fascinating read, told through an engaging narrative that both maps out Fuch’s activities but also tries to make sense of them.  The final chapters covering Fuch’s confession are particularly interesting because they seem so odd, Fuch’s being allowed to continue his work despite being under investigation and the slightly, amateurish comic cat-and-mouse game that was played out with British intelligence services.  Rossiter admits that there are holes in the story, but that in some cases they are never likely to be filled due to the lack of documented evidence, and in others the material is still classified.  Nevertheless, he’s done a good job of marshalling what material there is from archives in Britain, Germany and Russia providing a nicely told biography.