In the original 1972 edition of "Total War", the authors demonstrated why World War II happened, and how it was conducted, giving as much stress and space to political, social and moral forces as to ensuing clashes of arms, not forgetting the considerbale part that intelligence reconnaissance played in the war. This new edition takes into account new evidence that has come to light, especially from British sources, as, under the Thirty Year Rule, many official war documents are no longer confidential. Peter Calvocoressi has therefore rewritten much of the Western hemisphere section of the book in the light of this new evidence.