As revisionist, autocratic states like Russia sharpen their use—and abuse—of disinformation, liberal democracies are failing to keep pace. The Kremlin’s use of information as a weapon is not new, but its sophistication and intensity are increasing. Belatedly, the West has begun to realize that disinformation poses a serious threat to the United States and its European allies, primarily the “frontline states”—Poland, the Baltic states, the Czech Republic, Slovakia and Ukraine—but also to Western Europe and North America.