During the later parts of WWII the US had almost totally defeated Japanese encryption, and we could see everything they were saying. Japanese leaders knew they were losing, but wanted to fight to the last man because they believed that level of heroism might save them.
When Hiroshima was bombed, Japanese officials initially didn’t believe the reports of this new superweapon. It was only after Nagasaki that they finally agreed to surrender.
The war definitely wasn’t over before the nukes. The nukes ended the war.
WWII ended when the US nuked Japan. So you’re saying nuclear war?