The first edition of Changing Direction: British Military Planning for Post-war Strategic Defence, 1942–47, based on Julian's doctoral thesis in strategic studies, was published in 1988. A second edition, much expanded as a result of newly-declassified documents, was published by Frank Cass in 2003 [ISBN 0-7146-5399-3].
Professor Richard Aldrich (University of Nottingham): "Changing Direction is essential reading for anyone interested in the emerging Cold War and the new edition contains remarkable new material from the latest declassified files. It reveals the furious arguments of Whitehall warriors on the brink of a dangerous new conflict and captures the dilemmas of strategist, diplomats and the intelligence community – everything is here.”
Anthony Gorst (Millennium): “Changing Direction is the first work based upon archival research that deals with the making and evolution of British post-war defence policy ... Not only does Lewis present new material, based on exhaustive research, in support of his argument, but he has also secured access to material that is still retained by the Departments concerned.”
Foreign Affairs: “An intriguing narrative of the debate during World War II between the Foreign Office and the British Chiefs of Staff over two questions: which country would pose a threat to Britain after the war, and what the nature of future warfare would be.”
Professor R.V. Jones FRS: “Dr Lewis has enhanced the lessons of World War II by distilling from an immense amount of intricate labour such a discerning and objective account of British strategic planning.”
Professor M.R.D. Foot (English Historical Review): "His scholarship is as meticulous as [Official Historian Sir Harry] Hinsley's ... his book also is of absorbing interest."
Economist: "... adds greatly to public understanding of how secret business was conducted in mid-century ... based on hitherto highly secret archives."
Lord Beloff (Encounter): "... an important contribution to the understanding of the origins of 'the Cold War' and ... the inevitably contingent nature of all military and political planning."
Dr Richard Moore: "... a highly readable account of the rise of the Soviet threat through British military eyes."
Dr Raffi Gregorian: "Lewis's work is the single, most comprehensive study that exists of British planning during this period, being an almost week-by-week account of the iterative planning process from 1942 to 1947."
Peter Hennessy (Attlee Professor of Contemporary British History, University of London): "When Changing Direction was first published in 1988, it told us many things we did not know about the most secret parts of Whitehall. Thanks to the ending of the Cold War and an enlightened archives policy, the 1990s saw a bonanza of disclosures. These Dr Lewis has scooped up with great aplomb ... A fascinating read!"