The character of Fowler in Graham Greene's The Quiet American is that of a soldier during the Vietnam war who works side by side with a soldier named Pyle. Fowler and Pyle are exact opposites. While Fowler is realistic, tries to be tough, and despises being there, Pyle is a patriotic, naive and inexperienced soldier that has learned to understand that there could be a positive ending to the War. For this reason, Pyle becomes philosophically identified with the cause of the War and actually develops and idealistic view of what the war represents.
Pyle's attitude infuriates Fowler for all the obvious reason. After all, it is Fowler who sees this type of behavior as a weakening type of innocence.
I thought, ‘What’s the good? He’ll always be innocent, you can’t blame the innocent, they are always guiltless. All you can do is control them or eliminate them. Innocence is a kind of insanity.’
Therefore, when Pyle is killed in battle, his ideas, philosophies, and dreams die right along with him. In Fowler's eyes, if Pyle had realized the reality of war, he would have done more to protect himself and ensure his survival. In Fowler's eyes, Pyle is dead because of his innocence, rather than for any other cause. Naivete and innocence do not mix well in a scenario for survival.