The whole concept of "good vs. evil" is a human construct. Our species has used it to dehumanize those we wage war against since the earliest days of organized militaries. It transcends culture, nationality, and our time on this planet; it has always been and will always be.
America's own relationship with warfare is as nuanced as any other nation in history. Some wars have been waged under historically just causes, some have not. We have fought foreign occupiers of our own land, indigenous occupiers of their land, ourselves, our neighbors, foreign invaders, and numerous people abroad.
In all of it, like those before and after us, war has been over economic advancement, independence, territorial expansion, revenge, and, on occasion, simply to do what's right by our fellow humans — and in our young nation's history of war, we've encountered sweeping victory, stalemate, and utter loss
No matter the circumstances of war, we can always cite shining moments of heroism, grit, and honor that has come from those in the proverbial and literal trenches. It's a testament to the toughness bred into the individuals of this land. It has always been and will always be there.
We can always give comment in hindsight on the morality of our conflicts, but one thing is certain: Americans will always come to fight when called.