The bombing of Nagasaki, occurring just 75 hours after Hiroshima, played a critical role in Japan's decision to surrender during World War II. Contrary to a common perception that the destruction of Hiroshima alone prompted Japan's capitulation, military leadership in Tokyo did not immediately convene or alter their war strategy. Many believed Hiroshima was an isolated event, and that the United States likely possessed only a limited number of the extraordinarily expensive atomic weapons.
This belief, that Japan could withstand a single atomic attack and potentially negotiate better terms after a costly invasion, was shattered by the events in Nagasaki. The swift destruction of a second major city demonstrated that the U.S. might possess an almost unlimited supply of atomic bombs. This realization eliminated the hope of forcing a negotiated peace through a prolonged invasion, as the U.S. could now potentially annihilate Japanese cities sequentially.
James M. Scott, quoted in Time, notes that public memory has largely elevated Hiroshima to a universal symbol of war's tragedy and the horror of atomic weapons, while Nagasaki has faded from prominence. However, the strategic impact of Nagasaki was profound, convincing the Japanese leadership that continued resistance was futile in the face of an enemy capable of leveling cities at will.