LONDON – On August 6, 1945, the first uranium bomb was exploded above Hiroshima with the force of 15,000 tons of TNT. A total of 140,000 people died that year as a result of the blast and fireball that engulfed the city, falling debris, and the radioactive fallout. Three days later, Nagasaki was shattered by a plutonium bomb that matched the design of a bomb that the United States had tested in the New Mexico desert three weeks earlier.
The success of that test prompted the Manhattan Project’s lead scientist, Robert Oppenheimer, to reflect that he had become a “destroyer of worlds.” Over the next 40 years, the five permanent members of the United Nations Security Council (the US, the Soviet Union, the United Kingdom, France, and China) amassed roughly 70,000 nuclear weapons, with a combined explosive force of 15 million tons of TNT.
This October will mark the 50th anniversary of the Cuban missile crisis, when US President John F. Kennedy and Soviet Premier Nikita Khrushchev managed – by luck as much as judgment – to pull back from the brink of nuclear war. Miscalculation and saber rattling led to several more near-misses before activism by civil-society groups triggered a cascade of nuclear-arms reductions, reinforced by the Cold War’s end.
In the 1980’s, joint studies by US and Soviet scientists showed that a full-scale nuclear war between the Cold War’s superpowers would cause environmental devastation so severe that the ensuing “nuclear winter” could extinguish life on earth. These studies, along with public pressure, motivated Soviet Premier Mikhail Gorbachev to reach out to US President Ronald Reagan in 1986, resulting in some of the most comprehensive arms-control proposals in history.