That's the end purpose of war: to force other people into submission (if not to exterminate them). War is terrorism.
Of course there are methods and methods, there have been many theories of "just war", and many "laws of war" made. They've all been an effort to limit the "terrorist" aspect of war, but ultimately if you want to win you have to terrorize the enemy into submitting. That's the purpose of bombings such as the Hiroshima bomb.
Consider: if you want some kind of "unconditional surrender", because you want to change the way your enemy conducts some actions (their system of government, their willingness to attack others in the future, trade concessions, territorial concessions, etc) does it suffice to destroy their military potential and then cease all operations? No. All those goals require a change in the civilian structure of the enemy state. To achieve that its civilians must be forced to comply with your demand. And if you do it through war, then hold no illusion: you achieve it by threatening, terrorizing them.
For an example: the US did not change Iraq's government by being nice and talking to the Iraqis about it. It achieved that by arresting or outright killing all those who actively resisted the change, and making like miserable to those who passively resisted, so miserable that surely many of them also died (and this is not getting into the death toll of the embargo prior to the war). Wars are bloody, and no side is made up of saints. If people kept themselves aware of this perhaps they would not be so quick to support starting new wars. I believe that is the point Flying Pig has been trying to make.