Seventy-five years ago on  August 6, in a monstrous genocidal attack, the U.S. military dropped an atomic bomb on Hiroshima, Japan [and two days later on Nagasaki], slaughtering more than 300,000 innocent civilians in the two cities, plus untold tens of thousands who would die later or suffer the poisonous effects from the radiation unleashed by the two bombs.  
The racist U.S. rulers, murdered masses of people in Japan to intimidate their rival, the then socialist Soviet Union.  The then floated the lie that the A-Bomb attacks were necessary to “force Japan’s surrender and avoid a U.S. land invasion of Japan involving 1,000,000 U.S. casualties.” All while the U.S. bosses knew full well Japan’s rulers were ready to surrender BEFORE the atomic bombings.
Atomic bombings not necessary to end the war
  The United States Strategic Bombing Survey reported that, “Certainly …in all probability prior to November 1945, Japan would have surrendered even if the atomic bomb had not been dropped…and even if no invasion had been planned or contemplated. (trumanlibrary.gov, Japan’s Struggle to End the War)
 General (later president) Eisenhower said it was his “belief that Japan was already defeated and that dropping the bomb was completely unnecessary…and no longer mandatory to save American lives.”(Mandate for Change”; 1963)
 General Douglas MacArthur, U.S. Pacific commander, believed the dropping of the bombs was “completely unnecessary from a military point of view.”(The Years of MacArthur; Vol. II)
 The LA Times reported in “The Myths of Hiroshima” (8/5/05) that, “The hard truth is that the atomic bombings were unnecessary. A million lives were not saved. Indeed, McGeorge Bundy, the man who popularized this figure, later confessed that he had pulled it out of the air to justify the bombings in a 1947 Harper’s Magazine essay that he had ghostwritten for Secretary of War Henry Stimson.”
 On March 9, “100,000 to 200,000 men, women and children died when the U.S. Air Force doused Tokyo with jellied gasoline….In the months before Hiroshima [conventional] bombs killed up to 500,000 in Japanese cities and left 13 million homeless.”(U.S. News & World Report, 7/13/95)
By the Spring of 1945, Japan’s entire industrial and military machine had ground to a halt, severing its military’s lifeline.
By June, U.S. Air Force General LeMay complained that there was nothing left to bomb in Japanese cities except “garbage can targets.” [In fact, Truman’s Secretary  of War Stimson told Truman that he was “fearful” that before the A-Bomb was delivered, the U.S. Air Force would have Japan “so bombed out” that the A-Bomb “would not have a fair background to show its strength.”]
So, if not necessary to end the war, why was the bomb dropped?
In May 1945, Soviet leader Josef Stalin had promised U.S. president Truman at the Yalta Conference that the Red Army would enter the war against Japan within three months after the Nazi surrender in Europe, which occurred on May 8, 1945. On August 8, the Soviets swept into Manchuria and were preparing an invasion of Japan. “It was the Soviet Union’s entry into the Pacific war on Aug. 8, two days after the Hiroshima bombing that provided the final ‘shock’ that led to Japan’s capitulation.” (LA Times 8/5/05)
The U.S. ruling class not only wanted to prevent any Soviet participation in peace settlements with Japan but also to use the bombings as a display of U.S. military might, a political warning to the Soviet Union of what awaited it in the post-war world.
Rather than the last act of World War II, the atomic bombings signaled the U.S. launching of the Cold War.
The U.S. ruling class aims for the driver’s seat vs. the Soviets in post-war world
Truman’s War Secretary . Stimson, in referring to the Bomb as a “master card,” said, “Let our actions speak for words. The Russians will understand them better than anything else….We have to regain the lead…in a pretty rough and realistic way….We have coming into action a weapon which will be unique.” (Stimson Diary)
 Atomic bomb scientist Leo Szilard, in a meeting with Truman’s Secretary of State James Byrnes, said: “Mr. Byrnes did not argue that it was necessary to use the bomb…in order to win the war….Mr. Byrnes’s view [was] that our possessing and demonstrating the bomb would make Russia more manageable in Europe.” (Szilard: A Personal History of the Atomic Bomb”; 1949)
Truman and Byrnes quite plainly used the Bomb primarily to prevent the Soviets from sharing in the occupation of Japan. As Churchill had said about the Bomb, “We now had something in our hands that would redress the balance with the Russians.” (LA Times 8/5/05)In what amounted to an indictment of the liberal Democrat Truman administration, atomic scientist Szilard stated that, “If the Germans had dropped atomic bombs on cities…we would have defined [it]…as a war crime, and we would have sentenced the Germans who were guilty of this crime to death at Nuremburg and hanged them.” (Szilard: A Personal History of the Atomic Bomb”; 1949)
It remains the historic task of the international working class to smash the most murderous war criminals the world has ever known.