Nagasaki is a city on the island of Kyushu in Japan. After the Tokugawa Shogunate closed off Japan to foreigners, Nagasaki was the only port still open to European traders.
On August 9, 1945, in World War II, an atomic bomb called Fat man was dropped on Nagasaki by the United States, destroying large parts of the city.
After the destruction of Hiroshima, the military leaders still rejected an American military occupation, disarmament, and war crimes trials conducted by the victors. News of the Nagasaki bomb was decisive, not in changing their minds, but in motivating the civilian leaders and Emperor Hirohito to face reality. 
- ↑ Alonzo L. Hamby, "The Decision to Drop the Bomb," Journal of American History, Vol. 84, no. 2 (September 1997)