@flutherother The Empire stated outright that it wasn’t going to surrender. The government fully planned to fight ground forces until every last Japanese was dead. At this point, Japan’s defeat was a given; it was just a question of time and casualties. The first bomb didn’t do it, and Wikipedia suggests that the second one wouldn’t have either if not for the fact that the Soviets declared war in between them.
There were ten days between the Potsdam Declaration – effectively a “surrender or be destroyed” ultimatum – and the bombing of Hiroshima. There were another three days before Nagasaki. In all, it took nearly two weeks for the Emperor to tell the Supreme Council for the Direction of the War how things were going to be.