Fine in Very Good jacket, Book Club Edition, Very slight signs of age to DJ, no real damage. Techniques used to mislead the enemy, the deployment of fake tanks, planes & even soldiers; phony bases & airports which looked real from the air; build-up of troops & equipment to suggest an attack when none was planned, vital part in preventing the invasion of Britain in 1940, preparations for the crucial battle of El Alamein & in deceiving the Germans about the Allied invasion of Europe.