S. had responded by offering the retention of the Japanese Imperial Monarchy instead of insisting on unconditional surrender. Further research on the decoded messages, however, indicate that the militarists still dominated the power hierarchy in Japan and they were willing to fight to the bitter end, despite their precarious military position. They were depending on the war-wariness of the Americans. Their theory being that the United States was unwilling to bear more casualties and any major setback to the American forces during a planned invasion of the Japanese mainland would improve Japan's bargaining position and obtain a peace agreement. In other words, the Japanese military leaders were only agreeable to a ceasefire and unwilling to consider surrender. They wanted to retain the militarist policies of the government and with the hawks dominating the corridors of power, there were no chances of an early end to the War in August of 1945. It was only the shock of the devastating power of the atomic bombs, which broke the hold of the militarists over the Japanese government and enabled the doves to consider surrender (Wainstock, 1996, pp. 44-57; Frank, 2005) All of above, by no means suggests that President Truman's decision to use the atomic bomb was based solely on the desire to end the war quickly and save lives. Other considerations may well have played a part in the decision albeit to a lesser extent. For example, the Manhattan Project initiated for the development of the atomic bomb had cost over $2 billion, which was an enormous amount for the time. President Truman must have been under considerable pressure to justify the expenditure to the Congress if the bomb had not been used. The potential rivalry of the United States with the Soviet Union in...

Most of all, the American public's desire for revenge and to punish the Japanese for its attack on Pearl Harbor and its atrocious treatment of American prisoners meant that Truman would not have felt any remorse for ordering the devastating attacks.
The dropping of the atomic bombs on Hiroshima and Nagasaki on August 6 and 9, 1945 respectively demonstrated the awesome power of the most lethal weapon ever devised by man. Although there were several reasons behind President Truman's decision, his desire to end the War quickly and to save American lives was the primary motive.

References

Frank, R.B. (2005). "Why Truman Dropped the Bomb." The Weekly Standard.

08/08/2005, Volume 010, Issue 44.

Truman, the Bomb, and What Was Necessary." (2005). Seattle Times News Services, August 06, 1995. Retrieved on October 4, 2007 at http://archives.seattletimes.nwsource.com/cgi-bin/texis.cgi/web/vortex/display?slug=2135131&date=19950806&query=President+Truman%2C+in+a+speech+on+August+6%2C+1945

Wainstock, D.D. (1996). "The Decision to Drop the Atomic Bomb." Praeger: Westport, CT.

18,000 American soldiers were killed during the fighting at Iwo Jima and Okinawa, while 120,000 Japanese troops and 42,000 civilians died in a fanatical defense of Okinawa alone ("Truman, the Bomb, and..." 1995).

There are various estimates of the expected American casualties during an invasion of the mainland ranging from a couple of hundred thousand to a million; estimates for Japanese casualties were several times higher (Ibid.)

Atomic Bomb