In 1921 MI5 commissioned a detailed review of the organisation's operations during the First World War. The survey, amounting to over 270,000 words in seven volumes, plus appendices, remained classified in MI5's registry and was only used in Whitehall to argue against budget cuts. MI5 in the Great War is a version of that top-secret history, concentrating on the main narrative of the Secret Intelligence Service's activities in the war, edited and brought up to date by bestselling writer and historian Nigel West.