At Potsdam, the Soviet Union reaffirmed its promise to declare war on Japan.154 Potsdam marked not only the end of the war in Europe but also the beginning of a new era for humanity, the atomic age. The first tests of the atomic bomb had taken place in the United States on the eve of the conference. Churchill and Truman were excited. According to Field Marshal Alanbrooke, Churchill
was already seeing himself capable of eliminating all the Russian centers of industry and population without taking into account any of the connected problems, such as delivery of the bomb, production of bombs, the possibility of Russians also possessing such bombs, etc. He had at once painted a wonderful picture of himself as the sole possessor of these bombs and capable of dumping them where he wished, thus all-powerful and capable of dictating to Stalin.155
Both Truman and Churchill were surprised by Stalin's indifference toward the news of the detonation of an A-bomb. It was said that either he did not understand or he underestimated the importance of the new weapon. In reality, Stalin was fully aware of what had taken place but was clever enough to hide his feelings.
Two years before the tests in New Mexico, the Soviets had already begun to investigate thermonuclear reactions. At the end of 1942 Georgy Flerov, one of the most capable Soviet physicists, along with his colleague K. A. Petrzhak, had discovered the spontaneous disintegration of plutonium. He explained his findings in a letter to Abram Ioffe, the father of Soviet nuclear physics, and to the State Defense Committee, urging them to focus attention immediately on the problem of harnessing atomic energy and developing an atomic weapon. At more or less the same time another Soviet physicist, Igor Kurchatov, was summoned to Moscow to meet with a group preparing a report on the subject to the Central Committee. The report was given a favorable hearing, and a special bureau was established under Kurchatov. It was not until Stalin returned from Potsdam, however, that special attention was accorded to the atomic project. Beria, the head of state security, was placed in charge of the project, and enormous resources were allocated to it. Soviet intelligence was ordered to devote its efforts to obtaining atomic secrets, and it succeeded in obtaining a great deal. By December 1946 the first Soviet atomic reactor was built.
This example shows quite instructively how history works, how events in one field have an immediate effect on other fields. In Stalin's first postwar policy statement, made in connection with the elections to the Supreme Soviet on February 9, 1946, he stressed that it was essential to encourage scientific research.156 Scientists' salaries were doubled or tripled, housing was built for them, and they were provided with better medical care than the rest of the population. It was at this point that the higher strata of the scientific community became an integral part of the top bureaucracy.
In April 1941 the Soviet Union had signed a neutrality pact with Japan. This pact served the Soviet Union well during the difficult first two years of war. Thanks to this pact, the Soviet command had been able to risk weakening the Far East and transfer significant military contingents west. The forty divisions stationed in the Far East were far from full strength. From many divisions entire regiments were transferred to the German front, leaving only their numbers as camouflage to confuse the command of the Japanese Kwantung army.
At the beginning of 1942 Japan had definitely abandoned all plans for war against the Soviet Union. After Germany's surrender the Japanese government sought several times to induce the Soviet Union to act as a mediator to end the war between Japan and the Western allies. One purpose of these overtures was to discourage Soviet entry into the war against Japan.
During the Potsdam conference the Japanese government offered to send Prince Konoye to Moscow to initiate talks. Stalin informed Truman and Churchill of the Japanese proposal, explaining that since the Japanese had not expressed willingness to surrender unconditionally, as the Allies insisted, the Soviet government had stated that it could not give a concrete reply to an inquiry made in such general terms.
At Potsdam Truman formally suggested that the Soviet government break its neutrality pact with Japan and enter the war against it, citing the Soviet
Union's obligations as a member of the United Nations. Both Truman and Stalin deliberately disregarded the fact that the UN charter had not yet been ratified; ratification came only on August 20, 1945, eleven days after the Soviet Union declared war on Japan.
But all these were mere legal arguments. Immediately after the end of the war with Germany, four Soviet armies had been hastily transferred to the Far East. Marshal Vassilevsky had been sent there as commander-in- chief, along with Marshals Malinovsky and Meretskov to direct operations. For Stalin, the question of war against Japan had long been decided. This issue had several aspects. On the military level, an offensive in the Far East and the destruction of the Japanese Kwantung army would give the Soviet Union the immense territory of Manchuria and enable it to establish strong points to the southeast of the existing Soviet borders. In the context of continuing civil war in China, the Soviet Union could become an influential force on the continent of Asia, capable of intervening in the affairs of China, Indochina, and Korea. Furthermore, Stalin thought of himself with pride as the man who had regained the lost lands conquered by imperial Russia. From this point of view, to defeat Japan in the Far East would be to avenge the defeat of Russia in the war of 1904. In addition, by participating in the war against Japan, the Soviet Union would acquire the legal and moral right to have a voice in all matters involving the Pacific region.
By the end of July the Soviet command had concentrated 1,500,000 men in the Far East (to the Japanese 1,040,000), 26,000 guns (against 5,360 for the Japanese), 5,500 tanks (against 1,155), and 3,900 planes (against 1,800).157 Soviet superiority was overwhelming, and the Soviets planned to break Japanese resistance in a very short time, before Japan's capitulation to the United States.
On August 6, the United States dropped the first atomic bomb on Hiroshima. Japan offered to surrender on the one condition that the rights of the emperor be respected. Demanding an unconditional surrender, the United States dropped a second bomb on Nagasaki. When news reached Moscow of the frightening consequences of the first bomb, the Soviet government, not wanting to be late to the "feast of the victors," declared war on Japan. This was officially announced on August 8. The next day the Soviet offensive in Manchuria began.
On August 14 Japan surrendered, in utter shock from the effects of the atomic blasts. Later, Soviet official historiography would say that the surrender was the result of the offensive in Manchuria. In reality, military operations in Manchuria continued until August 19—that is, five days after the unconditional Japanese surrender—when the commander of the Kwantung army, General Yamada, signed a statement of capitulation at Marshal
Vassilevsky's headquarters. The Soviet troops continued their offensive nevertheless, hoping to take as much Manchurian territory as possible and occupy all key points in Manchuria. The troops of the First Far Eastern Front entered Korea and reached the thirty-eighth parallel, the demarcation line agreed on by the American and Soviet armies.