Heinlein. His novellas "If This Goes On…" and "Solution Unsatisfactory" and his novel Sixth Column, all written before the American entry into World War II (Sixth Column springing in part from a Campbell idea), remain readable-and in print-today, while so much of the fiction of two generations ago has fallen by the wayside. "Solution Unsatisfactory" is an early and remarkably prescient attempt to define a problem that has plagued us ever since: How do you deal with the specter of atomic weaponry? The solutions we have worked out are as unsatisfactory as the one Heinlein proposed-but, as I said before, so far we've been both smarter and luckier than we might have been. As a graduate of the Naval Academy, Heinlein spoke with peculiar authority on matters military.

The brute fact of the atomic bomb hit popular consciousness hard after 1945. Nuclear war and its aftermath became a common theme in science fiction. Two early examples were Poul Anderson's stories later collected in the paste-up novel Twilight World, and those of Henry Kuttner collected as Mutant. Anderson in particular would go on to have a long and amazingly successful career, frequently revisiting military themes in a variety of contexts: most often in his future history peopled by such swashbucklers as Nicholas van Rijn and Dominic Flandry.

Another writer who did likewise was H. Beam Piper, till his unfortunate and premature death in the mid 1960s. His series of paratime stories of alternate history, particularly his fine last work Lord Kalvan of Otherwhen, revolve around matters military. So does the elaborate future history he built up, including such novels as The Cosmic Computer and Space Viking, which combines themes from medieval European warfare and the rise of Hitler in a most striking way.

Heinlein, of course, did not disappear after the war, either. In his juvenile novels (what would now be known as YAs), such as Between Planets, Space Cadet, Citizen of the Galaxy, and Red Planet, military themes either dominate or play a strong subordinate role.