During the course of the Second World War the Allies spent a good deal of time trying to work out how bombing might bring a country to collapse. In Italy’s case there is a good argument for suggesting that bombing helped to give the impetus to the overthrow of Mussolini and the Italian surrender in September 1943.

In the German case the Allies drew a blank. From early on in the war the RAF insisted that heavy bombing would unhinge the German war effort and perhaps bring about collapse without invasion. In the autumn of 1943 British intelligence suggested that conditions in Germany were worse