A hero–as we use the term in typical English discourse–is someone who voluntarily engages in rightful service to others, even though that service puts him at risk of harm, and who does so out of benevolence rather than a desire for personal gain. So, to assess whether soldiers are heroes, we’d need to know 1) what their motives are, 2) the degree to which they were at risk of harm, 3) whether they were rightfully serving others. The qualifier “rightfully” is important. After all, Nazi soldiers and Gulag guards served others, but they don’t serve the right ends, and they didn’t conduct their service in a morally permissible way...
Whether you think the typical American soldier is a hero or not will depend a great deal on your view of American foreign policy. Some American wars are beyond the pale; no reasonable person could believe them to be justified: e.g., the various wars fought to exterminate and uproot Native Americans, the Mexican-American War, and the Spanish-American war. What about other wars and military incursions? I’ll lay my cards on the table and say that I think hardly any US military actions have been justified according to the correct theory of just war. I didn’t think the invasion of Iraq was justified, and so far, it’s been a disaster. While the Taliban was of course an illegitimate regime, invading Afghanistan seemed like a terrible idea, and so far, it has been. It’s far from clear that US military actions over the past 15 years have done anything to promote or protect Americans’ freedom, though it is clear that these actions have wrought death, suffering, and destruction upon many innocent foreigners.--Jason Brennan, Bleedingheartlibertarians. [See also his follow-up.]
I have been a fierce critic of Jason Brennan in the past. But I have to recognize that given that Brennan is, in addition to being a professional philosopher, also, in part a public philosopher, it takes considerable courage to express the sentiments he does. Brennan risks hurting a promising career as a media pundit and other careers in public service by reminding Americans of some of the worst features of their history.
Unlike Brennan, I would argue that one can be courageous, even a hero, serving non-rightful ends. To oversimplify, the criteria for heroicism are spectator-relative. This is why the exemplary deeds recounted in Greek poetry remain heroic despite changing views on the laws of war and morality more generally. For, as the dictionary definitions remind us, a hero is admired. In fact, as Hume and Adam Smith both emphasized, even distant admiration of the dazzling hero is possible and co-existing with (subdued) moral disapproval.+ (Brennan's approving treatment of the quiet, everyday, dazzle-free heroicism the "local auto mechanic or your neighborhood tailor" is remniscent of Hutcheson's approach [recall]).
So, it's very hard for us to recognize our enemies as heroes, even if we, in our better moments, recognize their courage. That is, there are objective facts of the matter (ability as well as willingness to confront danger, fear, etc.) that make somebody's actions courageous and these are independent of morality. We are repeatedly told that suicide-bombers are cowardly, but this is just propaganda. If they attack, say, armed soldiers, we may abhor their tactics, but we would be foolish to fail to recognize their courage.*