"Secrecy was paramount. Neither the Germans nor the Japanese could learn of the project. Roosevelt and Churchill also agreed that the Stalin would be kept in the dark..." If anyone got wind of this project it could end in …show more content…
After hearing about the Trinity success, President Truman then informed Stalin that the US had a new weapon that could end the war. Many who were present reported that Stalin did not show any sign that he knew what that meant. But appearances are often misleading. "As it turned out, Stalin knew precisely what Truman was referring to. In fact, Stalin knew about the Manhattan Project long before Truman did. As vice president under Franklin D. Roosevelt, Truman had been kept in the dark about the atomic bomb. He only learned of it when he assumed the presidency after Roosevelt died suddenly in April 1945. Stalin, in contrast, first got word of the Americans ' atomic research three years earlier" (Arnesen). Spies had infiltrated the project, and while they were few in numbers, they had passed along many highly sensitive concepts and