America emerged from World War II as the most powerful nation on earth. Not only did it produce half of the world’s economic output, but it was also in sole possession of the most devastating weapon ever created. Initially, U.S. officials believed America’s nuclear monopoly would endure for some time. After the war, Gen. Leslie Groves, the brilliant manager of the Manhattan Project, predicted the Soviet Union would not explode its first atomic bomb for two decades.
The United States was therefore shaken when the Soviet Union entered the nuclear club on August 29, 1949. As harrowing as this experience was, it was quickly overshadowed by the prospect of Moscow acquiring thermonuclear weapons and the means to deliver them to the U.S. homeland.
The implications of this was brought into sharp relief on March 1, 1954, when the United States conducted its first test of a deliverable hydrogen bomb. Known as Castle Bravo, the scientists badly misjudged the yield of the bomb, which was about fifteen megatons compared to the five or six megatons they were expected. The resulting radioactive fallout went far beyond what the test team was expecting, nearly killing themselves. It did containment nearby islanders as well as the unlucky inhabitants of a Japanese fishing boat, Lucky Dragon, that happened to be in the area at the time of the test. All of the crew became sick, and one person died shortly after returning to Japan.
After the test, President Dwight D. Eisenhower’s science advisers superimposed the fallout patterns of the Castle Bravo test on a map with Washington, DC as ground zero. The results were shocking. As Annie Jacobsen recounts in her fantastic book on the history of DARPA:
If ground zero had been Washington, D.C…. every resident of the greater Washington-Baltimore area would now be dead. Without a Station 70–style bunker for protection, the entire population living there would have been killed by 5,000 roentgens of radiation exposure in mere minutes. Even in Philadelphia, 150 miles away, the majority of inhabitants would have been exposed to radiation levels that would have killed them within the hour. In New York City, 225 miles north, half of the population would have died by nightfall. All the way to the Canadian border, inhabitants would have been exposed to 100 roentgens or more, their suffering similar to what the fisherman on the Lucky Dragon had endured.
The prospect of the Soviet Union being able to wreak this kind of devastating on America not only terrified U.S. officials, but also created an enormous quandary for strategy. After all, America’s strategy was to use nuclear weapons to offset the Soviet Union’s quantitative advantages in Europe. This strategy was plausible when Moscow couldn’t retaliate against the U.S. homeland, and possibly if it could only do so with limited number of atomic weapons, but how could it be in an age of thermonuclear weapons that destroyed entire cities?
Civil defense was one idea to make the strategy work. The thinking was that if the United States could limit the damage the Soviet Union could do to the homeland, the threat to use nuclear weapons in Europe would be more credible. In the popular imagination, civil defense has become synonymous with the duck and cover drills in American schools. In reality, the plans were much more elaborate—though not any less insane.
Throughout the 1950s and into the 1960s, the U.S. government vacillated between plans that called for evacuating cities and ones that centered around building fallout shelters to allow urban areas to ride out the attacks. The responsibilities and roles of the federal, state, and local governments were also constantly in flux, and how much money to devote to these efforts was a frequent debate.