Philosophers have beaten war to death (pun intended). And it is generally agreed that war is only “good” (justifiable) when it is defensive or preemptive in the right way. For now lets just say that a war is justified when the world after the war (death and destruction included) is better by some standard than the world would have been without the war. Certainly this justifies the role the Allies played in WWII, since a world free of Hitler, even with the immense death and destruction created by the war, is certainly better than a world ruled by Hitler. And even if Hitler hadn’t been set on world domination it is likely that a preemptive war to get him out of power would have been justified. But this is not what I am going to discuss today, although it is a necessary background. What I am going to tackle here is the ethical repercussions of war, in terms of who is in the right and who is in the wrong. We talk about wars as though they were disagreements between people, and when people fight we can say that one or both of them is doing something that is ethically wrong. But a nation cannot do something that is ethically wrong because a nation is not an agent (an ethically responsible individual), only the people that make up the nation can.
Now in terms of assigning blame for a war there are three kinds of people we need to consider: citizens, soldiers, and leaders. Now if the war is just then clearly the citizens aren’t to blame, and there is nothing to consider. But if the war is unjust things become more complicated. Clearly citizens who oppose an unjust war can’t be blamed, but even citizens who say they support the war, if they do nothing, can’t be blamed (although they have done nothing worthy of praise either). So the citizens that are responsible for an unjust war are those who have in some way contributed to it, and there are two possibilities for this. One, obvious, possibility is that they have contributed to the war by supplying it, designing weapons, ect. The other possibility is that they have knowingly put leaders into place that were in favor of an unjust war, or were too incompetent to stay out of one.
Next we have soldiers. In the case of soldiers the obvious situation is soldiers fighting an unjust war, who clearly bear all the ethical blame for their actions (remember, claiming that you were following orders is no defense ethically). Here the complicated case is soldiers who are fighting a just war. Obviously if the war is justified then the actions the soldiers take to accomplish the war mist be justified as well, although this includes actions we would normally consider ethically blameworthy. Of course that doesn’t mean the violence committed in war is praiseworthy either. But even soldiers fighting a just war can do things that make them worthy of blame. In general any violence not necessary to accomplish the war is worthy of blame. Now this does not mean that all civilian casualties are grounds for blaming the soldiers, in even the most efficient war some civilian casualties are unavoidable, but clearly not all of the casualties that are the result of a war are justifiable in this way, and some soldiers may take even a just war as an excuse to kill. Of course cases in which the soldier does something ethically wrong with the idea that they are doing something right occur more often in war then they do in everyday life, but they are not confined solely to war, and can be dealt with as the usual cases are.
Finally we have leaders, which are the simplest case to deal with. If they order an unjust war then they are to blamed, and praised for ordering an just war. Of course if the leader has a more direct hand in the war, and gives specific orders to the troops, then we can judge them as we do soldiers (see above). And leaders also may mistakenly order an unjust war thinking it is just; as mentioned above such cases can be dealt with in the usual way.
So now that I have outlined who is responsible I must also outline to what extent they are responsible. Here the case of the soldier is the most obvious, they are responsible only for what they do. Leaders on the other hand are responsible for the whole war, which also should be obvious. Responsibility is complicated only when considering citizens who supported the war but didn’t play an active part in it. In terms of people who were supplying they war they should be responsible for whatever ills their aid made possible, meaning that those who did more to support the war are more responsible than those who did less. On the other hand, each of the people who knowingly put a leader that would start an unjust war in place also bear full responsibility for the war, it is not divided among them. The reasons why this responsibility isn’t divided are complicated, but they are the same reasons that lead us to say that all participants in a stoning are equally and fully responsible for the death; if we allowed responsibility to be diluted in group actions then we would effectively be condoning doing evil, so long as you get enough people to do it with you.