War in the Shadows

Espionage, subversion, Russians, Britons, Ukrainians. Who is the betrayer? Who the betrayed? Calder Walton’s “Spies” begins with a Ukrainian agent’s report to British intelligence. “The Russians admitted,” Mr. Walton writes, that “they could only hold on to Ukraine by force and that Ukrainians were ‘generally hostile to them and their ideas.’ ” We are in 1922, rather than 2022, but continuity across the past is a major theme of Mr. Walton’s ably constructed, well-written and widely grounded study of the past century of East-West intelligence conflict.