What was the most significant factor in presidential Harry s trumans decision to drop atomic bombs on Japan?

The most significant factor in President Harry S. Truman's decision to drop atomic bombs on Japan was the desire to expedite the end of World War II and minimize American casualties. Truman and his advisors believed that using the bomb would force Japan to surrender unconditionally, thus avoiding a potentially devastating invasion of the Japanese mainland. Additionally, demonstrating the power of the atomic bomb was seen as a way to strengthen the United States' position in post-war negotiations, particularly with the Soviet Union.