This book’s central thesis is in its title: the sharp rise in data available globally has generated new opportunities for states and nonstate actors to deceive and surprise opponents (and sometimes friends) in strategically important ways. Robert Mandel of Lewis & Clark College ambitiously identifies ways that attackers use data offensively and what targets can do to defend themselves. Mandel is not persuasive in all of his arguments, but he gets more than enough right to make a compelling case that intelligence analysts, the policymakers they support, and scholars who study both groups should pay much more attention to this issue.

Mandel first introduces strategically important facts of the information revolution and outlines propositions about how data overload and the ambiguity it creates can be used to manipulate people. A long chapter then presents, in a standard format, 10 case studies in reverse chronological order. Most concern the traditional focus of the literature on deception and surprise—armed conflict. Mandel also discusses President Donald Trump’s use of ambiguity in foreign policy, arguing unconvincingly that Trump relies only on ambiguity (p. 173), and the misleading use of information by Brexit advocates in the United Kingdom prior to Britain’s 2016 vote to l