Missouri's most visible impact during World War II was made by its native son, President Harry S Truman of Independence, Missouri. Less than three months after Truman took the oath of office as Vice-President, President Roosevelt died and Truman was immediately sworn in as the nation's 33rd President on April 12, 1945. At that time, Truman was suddenly thrust onto the world stage and assumed responsibility for handling international affairs, an area in which he had very limited experience. In fact, when Truman offered his condolences to Eleanor Roosevelt, Mrs. Roosevelt responded, "Is there anything we can do for you, you’re the one in trouble now." Later that evening, Truman acknowledged the enormity of his new position to reporters: “Boys, if you ever pray, pray for me now. I don’t know if you fellows ever had a load of hay fall on you, but when they told me yesterday what had happened, I felt like the moon, the stars and all the planets had fallen on me."
When Truman assumed office as president, he had no knowledge of America's top secret efforts to develop an atomic bomb. Within two weeks, however, Truman received a memo from Secretary of War Henry Stimson asking to discuss a "highly secret matter" that would significantly impact foreign relations. The following day, Stimson and Army General Leslie Groves met with Truman and provided details regarding the Manhattan Project. Truman learned that the United States was the only nation with the resources necessary to develop the atomic bomb at that time. During the meeting, Truman discussed whether to reveal the new weapon to America's allies and how the bomb would affect foreign-policy decisions. After much consideration, Truman authorized the continuation of the project and authorized an interim committee to advise the president on using the weapon.
On May 8, 1945, the Allies accepted Germany's surrender, thus ending the European Theatre of World War II. Almost immediately, however, President Truman confronted a myriad of issues regarding the administration and governance of war-torn Europe. Although President Roosevelt had addressed some of the post-war reorganization issues at the Yalta Conference back in February, Truman met with Winston Churchill and Joseph Stalin at the Potsdam Conference in July of 1945 to seek additional agreements. Great Britain and the United States were fearful that Soviet influence and communism would expand in Europe unless appropriate measures were in place. Some of the issues facing the participants included the administration of defeated Germany, the Soviets' occupation of Polish territory, the determination of reparations, elimination of National Socialism and Nazi policies, and the further prosecution of the war against Japan. Commanders from the Soviet, British, American and French military each took responsibility over one of the four designated occupation zones per agreements previously reached at Yalta.
During the Potsdam Conference, one of the issues facing President Truman was whether to adhere to President Roosevelt’s policy of concealing the United States’ development of nuclear weapons. Although Truman eventually told Stalin of America’s intent to drop a “powerful explosive” on the Japanese, he maintained secrecy regarding the existence of the atomic bomb. (Image 4) While some administration officials wanted to use the weapon to exact concessions from the Soviets, Truman believed that dropping the bomb would serve the collateral purpose of reining them in by indirectly threatening their security. Regardless, not only did the existence of the bomb enhance Truman's confidence as a world leader, it empowered him to negotiate more firmly in order to reach compromises.
One product of the conference was the so-called Potsdam Declaration in which the Allies issued an ultimatum to Japan to either surrender unconditionally or face total annihilation. Despite Japan's rejection of the ultimatum, Truman agonized over the decision whether to use the bomb. Ultimately, Truman’s choice to use the powerful explosive was based on the inevitable, extensive casualties that would result from an invasion of Japan. In making his decision, President Truman was mindful that the United States needed to prepare a well crafted press release explaining the weapon and his decision to use it. Truman ultimately approved the press release after many revisions and obtaining the input of the British.
After atomic bombs were dropped on the cities of Hiroshima and Nagasaki in August of 1945, Japan unconditionally surrendered on September 2, 1945. Fittingly, Japan signed the Instrument of Surrender aboard a battleship bearing the name of President Truman’s home state, the USS Missouri.