Some books mean more when read together with others. Jennet Conant’s compelling new history, The Irregulars: Roald Dahl and the British Spy Ring in Wartime Washington (Simon & Schuster, 2008) is in that class. It tells the story of British covert activity in the USA directed against opponents of America’s entering the Second World War, and also against Americans seeking to liberate the British empire and cut Britain out of important areas of postwar commerce. The focus of the story is Roald Dahl—yes, the Roald Dahl! In the spring of 1942, some months after Pearl Harbor, the then devastatingly handsome,…