The chief social concern in The Cruel Sea is, quite simply, World War II.

Although the war had been over for a half-dozen years when the book appeared in print, the subject was still one of close concern to the author and, no doubt, to most of his readers. Monsarrat's leading characters all focus on the necessity of fighting and winning the war. The Germans are — at least for the war's duration — "bastards."

Nevertheless, various comments show a perception by some characters, including the protagonist Lockhart, of a world not totally black and white, although each tries to have his particular shade of gray emerge dominant.

Certainly, too, Monsarrat shows the tension between those who are really fighting the war — risking their lives from day to day — and those who are less fully engaged. Readers meet the cynical journalist, the uncaring wife...