The United States' bombing of Hiroshima and Nagasaki was the first time nuclear weapons were used in combat. This monumental event initiated, as John Hersey points out, the atomic age: countries around the world began to see the value in developing or obtaining such weapons in order to ensure their own security. This section provides a brief account of the global community's relationship with nuclear weapons throughout the last century.
The Manhattan Project, the United States' codename for the development of the first atomic bomb, began in 1941, after scientists Albert Einstein and Enrico Fermi fled oppressive Axis governments and warned President Roosevelt of the need to develop this technology before the Axis powers. The project employed over 120,000 Americans, but security was extremely tight, and only a few members of the U.S. and British governments knew of the project's existence. By the summer of 1945, Robert Oppenheimer, the scientist put in charge of assembling the bomb, was ready to test one, and on July 16, 1945, the world's first atomic bomb was detonated at a test site in New Mexico. On August 6 and 9, 1945, the results of the Manhattan Project, two bombs nicknamed "Little Boy" and "Fat Man," were exploded over Hiroshima and Nagasaki, Japan.
By 1949, the Soviet Union had tested its first atomic bomb, beginning the infamous nuclear arms race that would come to be known as the Cold War. Western democracies, like the United States, Great Britain, and France, all developed and tested their own nuclear weapons throughout the 1950s, all while the United Nations called for disarmament.
From October 16-29, 1962, there was an intense nuclear standoff between the United States and the Soviet Union after the U.S. discovered Soviet missiles in Cuba. For 13 days, the two powers teetered on the brink of nuclear war. The following summer, after many years at the negotiating table, the U.S., Great Britain, and the Soviet Union signed a Partial Nuclear Test-Ban Treaty in Moscow, which banned nuclear testing in the atmosphere, outer space, and underwater. On July 1, 1968, a more extensive Nuclear Non-Proliferation Treaty was signed, which has been adopted by 191 states thus far. Under this treaty, states that did not have nuclear weapons agreed to never acquire them, and states that had them took on a legal obligation to disarm.
In the later decades of the 20th century, nuclear disarmament became an even bigger topic of conversation, as the Soviet Union's leadership became more reform-minded and the Cold War died down. A total Nuclear Test-Ban Treaty was signed in 1996, banning nuclear testing of any kind. However, in the early 2000s North Korean nuclear proliferation became a new issue, and North Korea conducted its first successful nuclear test in 2006. Over the last decade, North Korea has conducted five nuclear tests, driving the global community to push even harder for disarmament and to try to stop the communist nation's proliferation.
On July 7, 2017, the United Nations adopted the landmark Treaty on the Prohibition of Nuclear Weapons, the first legally binding agreement pushing towards the total elimination of nuclear weapons.
