Why did Truman drop the bombs? Did he have another option? Why didn't the Japanese surrender after the first bomb was dropped on Hiroshima?

First question: He had no other option. Japanese forces were so good at prolonging U. S. Troops advancement that if he hadn't dropped the bombs the war could go on for months possibly years. He didn't want to drop them, but it was pressure from his advisers that it was a better option than losing anymore American lives. Second question: His other option was to continue what they were already doing, taking as much ground they could inch by inch until they took the country's capital. Third question: The Emperor of Japan hesitated thinking we couldn't possibly have a second bomb, which prompted the U. S. to drop another.