[vidarh]

That's the excuse that was given, but the regular bombings had been systematically doing precision raids during the day and indiscriminate firebombing during the night for months at that time. They were running out of significant cities to bomb well before Hiroshima, to the point where they'd started firebombing much smaller cities with no air defences or military presence to speak of as well - some of which were almost entirely obliterated.