When the attack on civilian populations serves no effective military purpose, they are immoral, and even worse, they are a mistake. Still, they need to taken in the context of the times. For example,during WW II "attrocities" against german civilian were commited by British, American and particulary Soviet militaries, but cannot be considered in a vacuum apart from the fundamental immorality of the Nazi war methods. The nuclear bombing of Japan is another matter, its justification as a means of avoiding the bloody reality of an invasion may be hard to justify retroactively, but a reasonable study of the history of the last year of the war shows that the very effective use of religiously motivated suicide warriors (i.e. kamikazees) against warships and troop ships resulted in an exagerated fear amongst US military planners of just how long, difficult and bloody the invasion would be.
U.S. says working on initiative to de-escalate Syria fighting, with focus on Aleppo (Reuters)
from the article: Leaving the home front out of range