Nagasaki
On the day of the nuclear strike (August 9, 1945) the population in Nagasaki was estimated to be 263,000, which consisted of 240,000 Japanese residents, 10,000 Korean residents, 2,500 conscripted Korean workers, 9,000 Japanese soldiers, 600 conscripted Chinese workers, and 400 Allied POWs. That day, the Boeing B-29 Superfortress "Bockscar", commanded by Major Charles Sweeney, departed from Tinian's North Field just before dawn, this time carrying a plutonium bomb, code named "Fat Man". The primary target for the bomb was Kokura, with the secondary target being Nagasaki, if the primary target was too cloudy to make a visual sighting. When the plane reached Kokura at 9:44 a.m. (10:44 a.m. Tinian Time), the city was obscured by clouds and smoke, as the nearby city of Yawata had been firebombed on the previous day. Unable to make a bombing attack on visual due to the clouds and smoke and with limited fuel, the plane left the city at 10:30 a.m. for the secondary target. After 20 minutes, the plane arrived at 10:50 a.m. over Nagasaki, but the city was also concealed by clouds. Desperately short of fuel and after making a couple of bombing runs without obtaining any visual target, the crew was forced to use radar in order to drop the bomb. At the last minute, the opening of the clouds allowed them to make visual contact with a racetrack in Nagasaki, and they dropped the bomb on the city's Urakami Valley midway between the Mitsubishi Steel and Arms Works in the south, and the Mitsubishi-Urakami Ordnance Works in the north. 53 seconds after its release, the bomb exploded at 11:02 a.m. at an approximate altitude of 1,800 feet.
Atomic bombings of Hiroshima and Nagasaki
The American monopoly on nuclear weapons lasted only four years before the Soviet Union detonated an atomic bomb in September 1949. The United States responded with the development of the hydrogen bomb, a nuclear weapon a thousand times as powerful as the bombs that devastated Hiroshima and Nagasaki. Such ordinary fission bombs would henceforth be regarded as small tactical nuclear weapons. By 1986, the United States would have 23,317 nuclear weapons, while the Soviet Union had 40,159. By 2017, nine nations had nuclear weapons, but Japan was not one of them. Japan reluctantly signed the Treaty on the Non-Proliferation of Nuclear Weapons in February 1970, but it still sheltered under the American nuclear umbrella. American nuclear weapons were stored on Okinawa, and sometimes in Japan itself, albeit in contravention of agreements between the two nations. Lacking the resources to fight the Soviet Union using conventional forces, the Western Alliance came to depend on the use of nuclear weapons to defend itself during the Cold War, a policy that became known in the 1950s as the New Look. In the decades after Hiroshima and Nagasaki, the United States would threaten to use its nuclear weapons many times.