questioned, while reviewers have said that the terms used to describe the aliens were akin to racial epithets. Despite the controversy, Starship Troopers had wide influence both within and outside science fiction. Ken MacLeod stated that "the political strand in [science fiction] can be described as a dialogue with Heinlein". Science fiction critic Darko Suvin wrote that Starship Troopers is the "ancestral text of US science fiction militarism" and that it shaped the debate about the role of the military in society for many years. The novel has been credited with popularizing the idea of powered armor, which has since become a recurring feature in science fiction books and films, as well as an object of scientific research. Heinlein's depiction of a futuristic military was also influential. Later science fiction books, such as Joe Haldeman's 1974 anti-war novel The Forever War, have been described as reactions to Starship Troopers. The story has been adapted several times, including in a 1997 film version directed by Paul Verhoeven with screenplay by Edward Neumeier that sought to satirize what the director saw as the fascist aspects of the novel. Writing and publication Robert Heinlein was among the best-selling science fiction authors of the 1940s and 1950s, along with Isaac Asimov and Arthur C. Clarke; they were known as the "big three" that dominated US science fiction. In contrast to the others, Heinlein firmly endorsed the anti-communist sentiment of the Cold War era in his writing. Heinlein served in the US Navy for five years after graduating from the United States Naval Academy in 1929. His experience in the military profoundly influenced his fiction. At some point between 1958 and 1959, Heinlein put aside the novel that would become Stranger in a Strange Land and wrote Starship Troopers. His motivation arose partially from his anger at US President Dwight Eisenhower's decision to suspend US nuclear tests, and the Soviet tests that occurred soon afterward. Writing in his 1980 volume Expanded Universe, Heinlein would say that the publication of a newspaper advertisement placed by the National Committee for a Sane Nuclear Policy on April 5, 1958, calling for a unilateral suspension of nuclear weapons testing by the United States sparked his desire to write Starship Troopers. Heinlein and his wife Virginia created the "Patrick Henry League" in an attempt to create support for the US nuclear testing program. Heinlein stated that he used the novel