2.	Why might Truman still decide to drop the bomb, even if he knew about Japanese desire to surrender?
There are several reasons reasons for his action:

To Shorten the war: The main reason for using the atomic bomb was to bring an end to the war as quickly as possible. The Allies had been fighting the war for years and the casualties on both sides were mounting. The atomic bomb was seen as a way to quickly end the war and prevent further loss of life.

To send a message to the Soviet Union: The United States had just emerged from the war as the world's leading military power. Dropping the atomic bomb on Japan was also seen as a message to the Soviet Union, who were considered a potential threat to American interests in the post-war world. By demonstrating the power of the atomic bomb, the US hoped to deter the Soviets from challenging American supremacy.

To pressure Japan to surrender unconditionally: The Japanese had been seeking a negotiated surrender, hoping to avoid the prospect of unconditional surrender. By dropping the atomic bombs, the US hoped to compel Japan to surrender unconditionally, thereby ensuring that the terms of the peace settlement were dictated by the Allies.

To avoid a ground invasion of Japan: The US was planning a ground invasion of Japan, which was expected to result in significant casualties on both sides. The use of the atomic bombs was seen as a way to avoid a ground invasion and bring the war to a quick end.

Till this day, historians still debate the decision to drop the atomic bombs on Japan and there is no one clear answer as to why Truman made that choice.
How long did it take for the Soviet Union to declare war on Japan after the US dropped the nuclear weapon on Hiroshima?
The United States dropped the first atomic bomb on Hiroshima, Japan, on August 6, 1945. The Soviet Union declared war on Japan on August 8, 1945, two days after the bombing of Hiroshima. The Soviet Union's entry into the war was a significant factor in Japan's decision to surrender, as it effectively cut off any hope of a negotiated peace. On August 9, the United States dropped a second atomic bomb on Nagasaki, and on August 15, Japan announced its surrender, officially ending World War II.
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