Robert Aldrich (Kiss Me Deadly, The Dirty Dozen) has never been about pre-made rules—or a world where morals and behavior are measured by a set standard. There is a reason why so many of Alrich's movies are war films. Aldrich is the creation, testing, and definition of ethics in a vacuum: men must decide for themselves what is right, and what is wrong, and how to act based on those decisions.
Here, the setting is World War 2, Jack Palance as a lieutenant fighting the desire, the need, to kill his murderously incompetent commanding officer. Where is the rightness in this situation? The agony over the ethics are plain to see: they are written forever on Palance's face. The man fails, but not through a struggle with his own conscience; he has decided to kill. Now he must struggle against nature, against his injured body; he must fight to master the ability to turn belief into action.
From Attack! (1956); featuring Jack Palance and William Smithers; directed by Robert Aldrich; cinematography by Joseph F. Biroc: