Studies of the role of intelligence operations inevitably have a "Rashomon"-like quality, with the same events yielding various, sometimes contradictory, interpretations.

The world of intelligence, after all, is one of secrets, special-access compartments, covert action, clandestine relationships and occasionally off-the-books escapades. This makes it very difficult to assess successes and failures, and to chronicle the role of intelligence in political leaders’ decisions.

Harvard historian Calder Walton confronts this challenge head on in a new book, “Spies: The Epic Intelligence War Between East and West,” which recounts the rise and role of modern intelligence capabilities through the history of the West’s competition with the Russian security services. It is an ambitious and entertaining story, but one that is also firmly grounded in academic research. In fact, Walton’s account sheds new light on seemingly well-studied events, from the Bolshevik Revolution and World War II to the deployment of moles in the ranks of American, British and Russian intelligence services at the end of the century.