For me, it's easy to see how the former mentioned virtues apply on a subjective reading of events: persons believe that they are fighting to preserve a higher good and thus puts themselves at risk to stand for what is good, save a comrade, etc. Yes, on the subjective level, persons are truly acting in a heroic fashion and this is what many cling to in order to make sense of their death or injury or to justify their killing of other human beings and the destruction of cities and the earth itself.
However, the objective or systemic component of morality often paints a different picture as has been well described by deceased General Smedley Butler:
“I spent 33 years and four months in active military service …. I served in all commissioned ranks from Second Lieutenant to Major-General... and during that period I spent most of my time as a high class muscle man for Big Business, for Wall Street and the bankers. In short, I was a racketeer, a gangster for capitalism. I helped make Mexico and especially Tampico safe for American oil interests in 1914. I helped make Haiti and Cuba a decent place for the National City Bank boys to collect revenues in. I helped in the raping of half a dozen Central American republics for the benefit of Wall Street. I helped purify Nicaragua for the International Banking House of Brown Brothers in 1902-1912. I brought light to the Dominican Republic for the American sugar interests in 1916. I helped make Honduras right for the American fruit companies in 1903. In China in 1927 I helped see to it that Standard Oil went on its way unmolested. Looking back on it, I might have given Al Capone a few hints. The best he could do was to operate his racket in three districts. I operated on three continents.... WAR is a racket. It always has been. It is possibly the oldest, easily the most profitable, surely the most vicious. It is the only one international in scope. It is the only one in which the profits are reckoned in dollars and the losses in lives.”
― Smedley D. Butler, War is a Racket: The Antiwar Classic by America's Most Decorated Soldier
Others conflate these components to serve their ends of domination, empire, resource control, etc. During these days surrounding Memorial Day, this conflation is most evident in the parades, church services, movies, poetry and song depicting the heroism and struggles of the average soldier. For one to say anything negative about the wars they fought is to be seen as critical and condemning of the soldier and their sacrifice. In this quagmire it is difficult to find any real objectivity.
Yes, it's most difficult to admit that the subjective goodwill and sacrifice of so many was done to serve the criminal interests of the few. But it can be done as Smedley Butler has shown, and as many current veterans of U.S. criminal wars have also done.* In taking that step, they have begun to reclaim their lives by resisting the crimes for empire that continues even today.
*Some examples of those who those who have taken a stand:
Iraq Veterans Against the War http://www.ivaw.org/
Veterans for Peace http://www.veteransforpeace.org/
Vietnam Veterans Against the War http://www.vvaw.org/