The writer is an FT contributing editor.

The British are indulging in one of their periodic bouts of spy fever, such as no other nation enjoys so much. Tinker, Tailor, Soldier, Spy is triumphantly launched as a movie, almost 40 years after the novel’s publication, when the Cold War was still pretty chilly. David Cameron’s visit to Moscow has reopened the six-year-old controversy about the London murder of dissident Alexander Litvinenko. There are red faces at M16 following the discovery in Libya of documents that expose a cosy relationship between the Gaddafi regime and Vauxhall Cross.

In intelligence matters, the British people get themselves in a considerable tangle about where reality ends and fiction begins. They reluctantly acknowledge that James Bond is a fantasy figure, but love the Man Who Never Was, the wartime corpse carrying deceptive documents that the clever British palmed off on the stupid Germans. Thanks to a muddle of Kim Philby, Anthony Blunt and John Le Carre, modern Britons think they know that most of the British Secret Service sooner or later turns out to have been working for the other side.

Yet, in an even more confused fashion, the British think spying is something we excel at. We may not be as rich as Americans, as good at making things as Germans, as cultured as the French or as energetic as the Chinese. But John Buchan was only the first of many writers to tell us that we play The Great Game jolly well.

There is something in this. But as a historian I am doubtful about the performance of British spies both before and after their glory days in the second world war...