Read “One Day in August” it is an excellent book and will change your view on history. It seems very plausible to me that while it is a true shame that so many lives were wasted, they would have been greatly offset by the capture of an Enigma machine. If you enjoy war history and are Canadian, it is a must read.
I've got O'Keefe's book and until it is proven to be historically incorrect, it makes more sense to me than any other theory justifying the Dieppe raid. Too many people and moving parts otherwise for just a coastal raid with little or no chance of success.