What did Britain really gain from the daring 1942 Bruneval raid?
These days we use radar to help us park our cars, but during the early years of the second world war it was white hot technology and a closely guarded military secret. First used to detect aircraft in 1935, within a few years it had helped win the Battle of Britain and sink the Bismarck. It was so secret that work on it was forbidden even to physicists of genius who had fled the Nazis. (In the event, this freed up two such émigrés, Rudolf Peierls and Otto Frisch, to prove the viability of the atom bomb and thus kick-start what became the Manhattan Project.) Intelligence about what the enemy
