Though Joseph Stalin is technically titled the General Secretary of the Communist Party of the Soviet Union's Central Committee, he is more widely known as the de facto leader and dictator of the Soviet Union from 1922 to his death in 1953.
Stalin rose from the humblest of origins, born in 1878 to a cobbler father and a serf mother in rural Georgia. After leaving seminary for financial reasons, he became an atheist and a prominent member of the Bolshevik revolutionary movement.
He also developed a close, though complicated, relationship with Vladmir Lenin, who would become the first leader of the USSR.
As dictator of the Soviet Union, Stalin maintained a complex and, at times, ambivalent relationship to his country's nuclear weapons program. In April 1942, he received a letter from Georgii Flerov, who noted that no physicist in Britain, Germany, or the United States had published anything on nuclear fission since its discovery three years before. However, Stalin did not choose to implement a Russian nuclear program at this time, most likely because he was still fighting the Germans in his own country.
On the other hand, it is possible that Stalin did not comprehend the importance of a potential atomic bomb. Two months before the US bombings of Hiroshima and Nagasaki, President Truman told Stalin at the Potsdam Conference that the Americans had "a new weapon of unusually destructive force." Stalin merely nodded his head, and did not ask any further information.
Weeks after the US bombings, however, Stalin made the Soviet nuclear program the country's highest priority, telling the scientific director of the program Igor Kurchatov to "ask for anything you like." In the wake up of the World War II, Russia was suffering from an enormous loss of resources, with 26 million people dead and another 25 million homeless. Despite the economic state of his country, Stalin allocated huge amounts of money for nuclear weapons development.
Stalin considered ending the United States' monopoly on atomic weapons so crucial that Kurchatov later said that he feared he would be shot if the nuclear program failed. Russia conducted its first successful nuclear test in 1949, during Stalin's lifetime, though the legacy of his nationalist determination outlived him.