The protagonist of Men at Arms, Guy Crouchback, has led a largely meaningless life in the years leading up to World War II. The outbreak of hostilities seems to offer an opportunity to find some individual purpose while at the same time serve his country, and he embraces it with a fervor that surprises everyone who knows him. But once in the army, Guy discovers that his new career is composed of decidedly mixed blessings: if stability and meaning are part of the structural bedrock of the military, so is an inflexible way of doing things that often leads to needless tragedy.

It is precisely these rigid dogmas of military discipline, however, which Guy comes to see as an integral part of the deep satisfactions he finds in military life. Without losing his intellectual awareness that such discipline can be stupid and even destructive, he achieves a more profound sense of the emotional loyalties evoked by the individual's commitment to the greater good of something larger than himself. He learns that in order to find some degree of personal fulfillment, he must first accept severe limitations upon his personal freedom, and it is this apparently paradoxical message that emerges from Men at Arms's thoughtful exploration of the relationship between private needs and public duties.