I wonder if a lot of people's idea of war has been shaped by the recent American occupations of Iraq and Afghanistan, which were wars of choice where at least in theory American soldiers were fighting largely for the benefit of the natives. Countries that believe they actually need to win and don't have the option of just giving up and going home fight wars in a very different way. Consider for example World War II, the proverbial "good versus evil" war fought by the generation that originally came up with the comic book characters you read about. The Allies certainly didn't hesitate to kill enormous numbers of Axis civilians in the course of destroying military targets. (IMO the Allies actually went way too far and a lot of the strategic bombing of Germany and Japan served no military purpose, but I suppose they were more worried about bombing too little than they were about bombing too much.)