Dwight Eisenhower's encounter with the Holocaust altered how he understood the Second World War and shaped how he led the United States and the Western Alliance during the Cold War. This book is the first to blend scholarship on Eisenhower, World War II, and the Holocaust together, constructing a narrative that offers new insights into all three, all while uncovering the story of how he became among the first to vow that such atrocities would never again be allowed to happen. From the moment he stepped foot in the concentration camp Ohrdruf in April 1945, defeating Nazi Germany took on a moral hue for Eisenhower that had largely been absent before. It spurred the belief that totalitarianism in all its forms needed to be confronted. This conviction shaped his presidency and solidified American engagement in the postwar world. Putting these pieces of the story together alters how we view and understand the second half of the twentieth century.