The Deep Six (1958)

The conflict between duty and conscience is explored in this WWII drama. Alan Ladd stars as Naval gunnery sergeant Alec Austin, a Quaker whose sincere pacifist sentiments do not sit well with his crew members. When he refuses to fire upon an unidentified plane, the word spreads that Austin cannot be relied upon in battle (never mind that the plane turns out to be one of ours).