atomic bomb

in july 1945, at a meeting of the allied leaders in potsdam, germany, president truman received word that the world's first atomic bomb had been tested in the new mexico desert. the bomb was the result of the top-secret manhattan project, started by roosevelt in 1942 after learning that german scientists were working on such a bomb.

truman faced one of history's most difficult decisions: to invade japan, the allies would need soviet help, but truman did not trust the soviet union. additionally, america's victories in the pacific had involved so many casualties that u.s. military leaders were concerned about the loss of life that would come with a full-scale invasion. if america used this terrifying new weapon, it might force japan to surrender without an invasion. however, it would mean a tremendous loss of life and property for the japanese. with great britain's support, truman decided to use the bomb.

the japanese surrender – august-september 1945

on august 6, 1945, the first atomic bomb was dropped on the japanese city of hiroshima by the enola gay, a b-29 bomber. a four-square-mile area of the city was destroyed, killing 80.000 people. the japanese military leaders refused to surrender. on august 8, the soviet union declared war on japan. on august 9, the united states dropped a second bomb on nagasaki, killing 35,000. the japanese finally surrendered. august 15 was v-j day –victory over japan– and world war 2 was over.