The difference was scale. It would have likely taken nearly all of the air assets the Allies had around Japan at the time to flatten one city with firebombs, and the Allies would have taken some losses in aircraft.
Now project out the idea that each of the dozens of planes used in a firebombing a city each only carried one bomb with the same flattened city as a result. It was projecting the idea that all cities in Japan could have literally been flattened in one day.
Now, we didn’t have the bombs or the air force assets to do that at the time, but that wasn’t known to the Japanese. Hiroshima was hit, then three days later Nagasaki. It would appear at the time as though the Americans were going to keep going every three days with a new city flattened with nothing the Japanese could do to prevent it except surrender.
One minor point: We had already flattened their cities with firebombs, so they knew we could do it without invading.
The difference was scale. It would have likely taken nearly all of the air assets the Allies had around Japan at the time to flatten one city with firebombs, and the Allies would have taken some losses in aircraft.
Now project out the idea that each of the dozens of planes used in a firebombing a city each only carried one bomb with the same flattened city as a result. It was projecting the idea that all cities in Japan could have literally been flattened in one day.
Now, we didn’t have the bombs or the air force assets to do that at the time, but that wasn’t known to the Japanese. Hiroshima was hit, then three days later Nagasaki. It would appear at the time as though the Americans were going to keep going every three days with a new city flattened with nothing the Japanese could do to prevent it except surrender.