After "The Day," as the nuclear attack becomes known in Alas, Babylon by Pat Frank, the community of Fort Repose rally around Randy, an unlikely leader in view of his former relaxed, almost playboy-type lifestyle. Recognizing the need to adapt because, as Randy notes himself, "Only the strong survive," Randy, a very competent lawyer, introduces laws to prevent chaos and helps the community adjust to its new way of life. Randy's no-nonsense approach and the introduction of a team of operatives for self-defense purposes ensures that everyone knows the consequences of criminal activity.
The community must manage without electricity and can no longer rely on the technology to which it was accustomed. Even medical supplies are compromised and Dr Gunn's discovery of hypnosis is a clever use of skills in replacing anesthetic. Being able to make the best of the resources allows the steadfast members of the community to manage food and water; the weather is mild and there is salt - a valuable commodity for food preservation in the absence of refrigeration. Even returning to the age old barter system is beneficial. The community learns by trial and error and some suffer when they do not take adequate precautions.
Survival is based on new rules and there is no room for old emotions. An overriding desire to live under any circumstance is the strongest new emotion sustaining this community. This would make a fitting thesis statement, supported by Ben Franklin's actions when he is basically forced to kill a dog and he is devastated at his own actions. Randy tries to make him understand that "it wasn't a dog anymore." Even the animals are having to adapt and a pet is now as threatening as a wild animal.
The thesis statement is further supported by Edgar Quisenberry's hopelessness. Those who cannot modify their behavior, cannot expect to thrive or even live as Edgar resolves:
How could life go on if dollars were worthless? How could anybody live without dollars, or credit, or both? … This was the end. Civilization was crushed.
Edgar's defeatist attitude will be his undoing.
The ending of the novel is possibly impractical and, although unlikely, it remains a testament to determination. In further supporting the thesis statement, the fact that "we really clobbered'em" becomes immaterial to the community and the decision to remain confirms that the colonel's words - "Not that it really matters-" suit this resolute community that has survived despite itself.