"The denial of moral absolutism leads not to relativism, but to nihilism."
Paul Boghossian, "The Maze of Moral Relativism"
I never thought I'd see a decent Captain America film in my lifetime, but this time Marvel has managed brio without ponderousness. When I was into comics in the 1980's, Cap was, it must be said, my favorite. While I enjoyed a number of titles, he eschewed the smart-alecky goofiness of Spider-Man, the self-involvement of the X-Men, and the contrived contortions of the Fantastic Four; sober but spirited, he was neither the hipster Batman nor the staid Superman (that George Washington of superheroes).
In the 1980's, shrouded by the forgetfulness of his reading public, Captain America bore little resemblance to the "old-growth superhero" (in A. O. Scott's memorable phrase) of the 1940's. Making up in steadfastness for what he lacked in flamboyance, he merely did his workaday thing month after obdurate month. In the new movie he reclaims a bit of the Nazi-slugging romance (Red Skull always was the villain par excellence, implacable and inscrutable without being ridiculous, compared to which Darth Vader was a clown).
Needless to say, Cap also embodies American exceptionalism as well as the absolute injunction to act morally. As Boghossian compellingly argues in his piece, if one wishes to avoid believing in nothing, it is logically necessary to believe in something. For the non-psychopath there is no evading moral dialogue (or in the case of comic book films, moral combat).