While I don't want to get involved in a political and radioactive topic (and don't intend to participate in an ongoing discussion), it seems to me there is something important to be said here.

To my mind, there are two critical moral differences between war and terrorism. The first is that the soldier attacks those who are fighting him - if not exactly the guilty, at least the active and resistant. The terrorist doesn't care if he attacks the weak and innocent and in fact prefers it. The second is that the object of a soldier's attack is to break the resistance, and he minimizes evil and suffering in pursuit of that goal. The terrorist maximizes it as a point of strategy.

Of course, fighting is sometimes necessary - evil must be resisted or it will dominate the earth. And in a messy real world, fighting often unavoidably hurts the innocent and the uninvolved - or even the involved in unnecessary ways. The desire to do things perfectly has to at some point yield to the need to do something - insisting that only perfect actions be taken is the same as saying no actions can be taken.

So what makes a fighting action moral? There isn't a bright line. At the margins, this is a judgement call. What level of violence, of what sort, is acceptable is something good people will have differing opinions on. But to suggest that the existence of a spectrum and the necessity of exercising judgement erases the categories is to commit the beard fallacy. The fact that we cannot say exactly when stubble becomes a beard does not mean there is no such thing as a beard - it just means the edges of the definition are fuzzy. That's actually normal! Most definitions have fuzzy edges, and have weak meaning on those edges. If one person wants a clean shaven man for some purpose and another wants a bearded man, both may consider a week old shave unacceptable for their purposes. Definitional edges have their interests, but don't necessarily inform how we think about centers.

Most ethics in war and in fighting turn on these ideas of innocence or powerlessness and necessity. Soldiers take prisoners (and treat them well) because taking someone out of the conflict is the honorable goal of war, and causing suffering once that is accomplished is evil. Criminals in prison (should) still have human rights for the same reason. I once heard a federal law enforcement official describe a shootout with a criminal, stating that the criminal was shooting at him and didn't care who else he hit, while the LEO was unwilling to return fire against the backstop of an occupied apartment building because that would be evil.

It does cost something to do things right - you pay for it in the blood of your own soldiers and in your chances of victory. One reason to seek an overwhelming force is to have the luxury of doing things as cleanly as possible. In a more even fight, at higher stakes, necessity may look different. People do take capabilities and circumstances into account when they judge you.

Nonetheless, there is a very big difference between doing the right thing imperfectly or even badly and doing the wrong thing. There are matters of degree between going to great lengths to avoid civilian casualties and accepting more of them. That does not mean intentionally targeting civilians exists on that spectrum. That's crossing an entirely different line.

On a personal level, in a self defense scenario, you can be taking actions to stop a threat or to hurt a person. The first is moral and legal; the second is immoral and illegal. And while you sometimes do the second in the course of doing the first, the minute you are doing it for its own sake, you are over the line. While we may disagree over where exactly the line is, that doesn't mean you can put it anywhere you find convenient. There is a moral truth to the situation.

Every criminal says they're acting in self defense through some twisted line of reasoning. And every terrorist can tell you why their targets are legitimate and their actions necessary. It is entirely possible to argue along such lines and to be wrong. Further down the thread, someone argues that targeting civilians is justified when those civilians vote for the government you are fighting. This is an example of careless moral reasoning that seeks to justify evil - you cannot know who voted how, and we do not kill people for how they vote or we find ourselves in the position of killing huge numbers of people. This is a thin justification for violence as a goal in itself. Likewise, someone argues that targeting the innocent is justifiable in a very asymmetric conflict. Again, this is a very thin justification. It is true that you are judged by the precision of your weapons and the options available to you, but a tenuous relationship to some strategic advantage doesn't justify egregious and pointless violence. At some point, it starts to look like the violence is the point to you and you're just evil.

These lines of argument highlight why I feel the need to respond. This erasing of the line between war and terrorism, which has apparently happened in the minds of a lot of people here, has an effect that is doubly harmful. It has the effect of hampering necessary and legitimate war by miring it in endless criticism and confusion about legitimacy. This is bad - when we fight evil, we need to be able to have intelligent conversations about how to acceptably do it. Overly hampering our capabilities helps evil be a little more dominant - keeps the bad guys a little more in control on the margins. Calling war terrorism commits this evil. But perhaps a worse evil is committed by calling terrorism war - it has the effect of justifying it! There are people in this thread who think that targeting voters and children is okay because they are confused about the concepts of innocence and necessity and in their confusion are incapable of intelligently evaluating reasoning that involves those concepts. It is not a great leap between finding terrorism morally acceptable and being willing to support it.

The ethics and morals of violent conflict - whether writ small between individuals or writ large between nations - have been a topic of discussion for all of civilization. While we don't always agree, a lot of important, intelligent, moral things have been said on the topic - things worth learning. We have concepts like war crime and terrorism for reasons. Contrary to (apparent) popular belief, there are not merely ugly sounds, linguistic weapons wielded for power. They are important and specific ideas, given to us by generations of thinkers, that help us distinguish between good and evil and understand the moral meaning of things. You erase those in your own mind at the risk of supporting and committing atrocities. It is important to know when the price of winning morally obligates you to lose, and when the price of losing morally obligates you to win. The ability to tell the difference comes, not from erasing lines, but learning how they are drawn and why.