American soldiers, marines, sailors, and airmen were still dying every day in the Pacific Theater. The Japanese may have been beaten, but they were still fighting. We would have taken one million casualties if we invaded the Japanese homeland. Faced with a decision between one more American life and however many tens-of-thousands or even hundreds-of-thousands of Japenese lives, Truman made the right choice.
Truman did the right thing.
The bombs ended WW II.