Hitler's "Final Solution" was an obscenity it is hard, mentally, to cope with (although similar obscenities have been perpetrated since). Because atrocities make good copy, WWII has been a popular focus for all sorts of fiction, fantasy included. More kindly one can propose that another feature of WWII made it particularly usable by fiction writers. Both World Wars were tragic, but WWI was remembered as an unmitigated tragedy, a grinding apocalyptic process whose outcome was always foreseeable, even though some of the details (like the USA's entry into the conflict) might have been unexpected at the time. WWII, on the other hand, has been remembered as a melodrama, full of strange and uncanny ups and downs, with terrifying new weapons galore, feats of derring-do on a daily basis, and protagonists who were not only Monsters in real life but also, in fictional terms, highly effective Icons of villainy. Despite the attempts of propagandists on both sides, no wholly evil figure emerges from WWI to occupy the world's imagination, no one of a viciousness so unmitigated that it seems almost supernatural; Hitler, on the other hand, has all the lineaments of a Dark Lord, and the Reich he hoped to found was a Parody of the true Land.
It is hard, on any other ground, to explain the fascination of the Hitler-Wins story. Either in the traditional form of the future-war novel that utters dreadful warnings or (after 1945) in the form of Alternate-World tales in which Germany prevails, the Hitler-Wins tale has been popular for well over half a century. The best are probably Sarban's The Sound of His Horn (1952) and The Man in the High Castle (1962) by Philip K Dick (1928-1992); the most popular recently has been Fatherland (1992) by Robert Harris (1957- ). In a cognate vein are tales in which occult or other supernatural forces are brought to bear – either by the Nazis (Himmler was a devout believer in the occult) or by forces in opposition to them – or in which characters return or Timeslip to a Nazi-controlled Europe, often in a Horror frame, with the Nazis often seen as vampiric or as in the clutches of a Dark Lord. Examples include: Dale Estey's A Lost Tale (1980; vt Fortress Island 1981), in which Druids protect the Isle of Man; Romain Gary's The Dance of Genghis Cohn (1967); Katherine Kurtz's Lammas Night (1983) and portions of her Adept sequence with Deborah Turner Harris; The Ring Master (1987) by David Gurr (1936- ); Barbara Hambly's The Magicians of Night (1992); William Kotzwinkle's The Exile (1987), whose protagonist timeslips into the body of a German black-marketeer, eventually to be trapped there after torture has driven the owner's mind forward in time and into the protagonist's own body; Roderick MacLeish's Prince Ombra (1982); Scott MacMillan's Knights of the Blood: Vampyr-SS (1993); Runespear (1987) by Victor Milán and Melinda Snodgrass; The Incredible Mr Limpet (1942) by Theodore Pratt; Jon Ruddy's The Bargain (1990), in which Hitler does a deal with Dracula; Lois Tilton's Darkness on the Ice (1993); several novels by Dennis Wheatley, including The Man Who Missed the War (1945) and They Used Dark Forces (1964); Connie Willis's "Fire Watch" (1982); and F Paul Wilson's Adversary Cycle, the first volume of which was filmed as The Keep (1983). Of the relatively few relevant alternate-world tales that do not focus on a Nazi victory, the most interesting is probably the WorldWar sequence (1994-current) by Harry Turtledove (1949- ).
Very occasionally the "Final Solution" has been approached by writers of the fantastic attempting to make sense of the event through a use of the tools of Fable, as in Jane Yolen's Briar Rose (1992) and Georges Perec's W, or The Memory of Childhood (1975). But there is a chariness about the use of overt fantasy to describe horrors which are too easily diminished through a genre generally designed for Escapism. Novels like The Birthday King (1962) by Gabriel Fielding (1916-1986), The Erl King (1970) by Michel Tournier (1924-2016), Herbert Rosendorfer's German Suite (1972), Thomas Pynchon's Gravity's Rainbow (1973), Michael Moorcock's Pyat sequence and Martin Amis's Time's Arrow (1991) are, fittingly, not fantasies – although the last can be read as such. But the black world they evoke has some of the characteristics of fantasy: a heightened sense, perhaps, of the horror of Bondage. Richard Condon's one true tragedy, An Infinity of Mirrors (1964), reads like a Fantasy of History caught in the bondage of the real WWII. Both The Key to the Great Gate (1947) by Hinko Gottlieb (1886-1948) and Slaughterhouse Five (1969) by Kurt Vonnegut (1922-2007) confabulate arguments about the nature of space and time in order to pry their protagonists loose from that bondage; in these two novels, an intense pathos underlies the "comedy" of escape. Tales like Poul Anderson's Three Hearts and Three Lions (1961) and L Sprague de Camp's and Fletcher Pratt's Land of Unreason (1942) catapult their heroes out of the nightmare into a Secondary World where acts of derring-do are more possible, and more palatable.
Less centrally, WWII has generated some Ghost Stories, like Death Into Life (1946) by Olaf Stapledon (1886-1950), whose dead pilot learns about the larger nature of the Universe, Robert Nathan's But Gently Day (1943), whose dead pilot has Posthumous-Fantasy experiences in the American Civil War, On a Dark Night (1949) by Anthony West (1914-1987), whose protagonist experiences after death a series of Hells, The Send-Off (1973) by Christopher Leach (1925-2004) and The Shepherd (1975) by Frederick Forsyth (1938- ), both the latter combining Belatedness and nostalgia as they involve the return of long-dead soldiers who evince no awareness of the passage of time.
The greatest fantasy to make use of WWII is probably Thomas Mann's Doctor Faustus (1947), in which both the composer Leverkühn and Germany itself are seen, by analogy, to have made similar Pacts with the Devil. [JC]