BTW, labeling something 'military target' (pretty arbitrarily, in this case) does not give one a moral free pass; indeed, it's only a particularly poor attempt at justifying whatever.
No the justifying comes from the fact that it was either this or an invasion of Japan, and considering how most attacks on Japanese held territory in the war went that WEREN'T their country it's safe to say such an invasion may have been a blood bath on both sides.
And in this case its justifying it as the lesser of two evils.
I already covered this argument:
"USA used the atomic bombs because it wanted to prevent further russian advances and to reduce the casualty number of its own soldiers (the relevant decision makers of the time admitted as much).
It didn't care in the least about reducing the number of japanese casualties or about any moral calculus along those lines - indeed, the japanese cities were chosen due to their geography (in order to focus the explosion, ensuring greater destruction/number of dead civilians) and to the fact that many buildings were made of wood (in order to burn, again ensuring greater destruction/number of dead civilians)."
Plus, it's doubtful that an invasion of Japan would have been even necessary - let alone be more costly in human lives than the atomic bombings.