On Seas Contested is not a history of the French, German, British, Italian, Japanese, American, and Soviet fleets at war, but rather gives us a surprisingly detailed profile of each of the principal navies in the Second World War, which includes some discussion of their operational experience. 

Each chapter focuses on one of the “Great Navies”, and is by a specialist in the field, such as Trent Hone on the U.S. Navy, Mark Peattie on the Japanese Imperial Navy, and O'Hara  on the Italian Royal Navy.  Chapters have a uniform format, addressing each fleet’s early history and mission, organization, personnel, doctrine, and ships and weapons, ending with a discussion of its overall problems and performance.  This common treatment of the seven navies permits more careful comparisons among them, leading to a clearer understanding of how they fought, why they did what they did, and how effective they actually were, which may help dispell the continuing influence of wartime propaganda and post-war memoirs, in which regard the essays on the French and Italian navies are particularly revealing.

An indispensable work for anyone studying the Second World War at sea.