i don't know how well-armed the civilians actually were, but the russian army would have killed scores of them armed or not
and as we saw and is documented okinawa, the civilian had been trained to fear rape and torture in the event of an american invasion, and would commit mass suicide rather than submit to invading americans
there are no innocents in war, to be sure, but i doubt the intention of revenge influenced the decision to drop those two bombs
i have no sympathy for imperial japan during those years, though
had they not committed the heinous acts around the world leading to their eventual defeat (the least of which being the attack on pearl harbor, if you do your research), there never would have been a reason to make such a terrible decision
they reaped what they sowed