I am deeply grateful to the many individuals who put their knowledge and expertise at my disposal during the course of writing this book. Unfortunately, I cannot give due credit to some of those people to whom I owe the greatest debt in understanding the intelligence issues, because they spoke to me on condition that I keep secret their identities.
I greatly benefited from the insights, erudition, and criticisms provided by those who read draft chapters at various stages of my investigation. I am particularly indebted in this regard to Tobias Brown, Rachelle Bergstein, Richard Bernstein, Sidney Blumenthal, David Braunschvig, Ash Carter, Susana Duncan, Joe Finder, Ben Gerson, Andrew Hacker, William Haseltine, Eli Jacobs, Bruce Kovner, Robert Loomis, Gary Lucas, John Micklethwait, Frederick Mocatta, Andrew Rosenberg, Curt Sawyer, Sean Wilentz, and Ezra Zilkha.
I am especially grateful to Harold Edgar, the Julius Silver Professor in Law, Science, and Technology at Columbia Law School; and to Jack Goldsmith, Henry L. Shattuck Professor at Harvard Law School, for sharing with me their legal perspective on the espionage statutes and other legal issues.
I thank Edward Lucas of The Economist for recommending Catherine A. FitzPatrick, a writer and translator at The Interpreter magazine as someone who “possesses a unique knowledge of the labyrinthine world of Russian disinformation.” She proved a godsend for this book. With her deep understanding of the workings of the Internet, she helped me retrieve information from the dark side of the Internet that I otherwise would not have found.
Because I do not believe an investigative book should be written without the author visiting the crime scene and other pertinent venues, I undertook research in Hawaii, Japan, Hong Kong, and Moscow. Where possible, I flew the same flights that Snowden did. I am grateful to Ena and Ines Talakic for their assistance on these research trips. As talented documentarians in their own right, they filmed a number of my interviews on these trips, and generously provided photographs for this book. I thank Alexander Bitter in Hawaii, Joyce Xu in Hong Kong, Ko Shoiya in Japan, and Zamir Gotta, Natalie Filkina, and Svetlana Chervonnaya in Russia for their help in arranging my interviews in those places. I also owe special thanks to Nick Grube, an editor at Civil Beat in Honolulu, for accompanying me to the NSA base where Snowden was working in 2013.
I am indebted to Nancy Novick for her skill, patience and enterprise in helping me find the selection of photographs for this book.
I am grateful to Zachary Gresham for his meticulous fact-checking and proofreading, and to Ingrid Sterner for her immensely helpful copyediting skills. Because I perform all my own research, I alone am responsible for any errors that appear in this book.
Mort Janklow, who has represented me for three decades, did a superb job in arranging for Alfred A. Knopf to publish this book.
I am thankful to Julia Ringo and the team at Knopf for their help in preparing this book. Finally, I am deeply indebted to Jonathan Segal for meticulously editing this book. The manuscript gained immeasurably from both his keen eye and his wise judgment.