The history of the Cold War is littered with what-ifs, and in Diplomacy Shot Down , E. Bruce Geelhoed explores one of the most intriguing: What if the Soviets had not shot down the American U-2 spy plane and President Dwight D. Eisenhower had visited the Soviet Union in 1960 as planned? In August 1959, with his second term nearing its end, Eisenhower made the surprise announcement that he and Soviet premier Nikita S. Khrushchev would visit each other's...