We laud veterans for having "fought for their country" regardless of what the fight may have actually accomplished. For example, many people who regard the Vietnam War as a failure--or worse, a moral atrocity--still hold Vietnam vets in high regard. It strikes me that reverence for veterans rarely considers whether their actions actually made any of their countrymen better off (never mind people in other countries). We have a notion of honorable military service that is tenable only insofar as it abstracts away the actual practical outcomes of warfare. When we praise a veteran, what exactly are we praising them for?

One morally important distinction here is between conscripted and voluntary military service. As you are probably aware, the United States currently has an all-voluntary military; every soldier is a soldier by choice. This has not always been the case (either in the U.S. or elsewhere). Nations sometimes requires military service of all citizens as a matter of course and/or utilize a draft during wartime. Let's focus first on those whose service is voluntary. Our attitudes toward those who volunteer for military service are, in my estimation, incoherent. We have become too quick to "thank them for their service" without due concern for the morality of their service. Classical just war theory divides the moral appraisal of war into two: there is the question of whether a nation's waging war in a given set of circumstances is just, and there's the question of whether a war is justly waged (whether, for example, the tactics or strategies used to pursue victory are just). Soldiers can therefore err morally...