The United States is the first and only country to use nuclear weapons in the history of the world. These attacks came in August, 1945, during the final stages of World War II against the Empire of Japan. Two cities targeted by the U.S. were Hiroshima and Nagasaki. The war in Europe was over in May of that year, with Nazi Germany's surrender, but the Japanese carried on. The U.S. and its allies conducted a firebombing campaign against the Japanese. It devastated the country, but they would not surrender. The allies were looking at a costly campaign to invade the Japanese mainland. The Japanese were determined to fight to the last person to defend their country, if necessary. This was a major factor in the decision to use the atomic bomb.