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 americ…