Science Fiction

The Forever War (1974)
Forever Peace (1997)
Forever Free (1999)

http://en.wikipedia.org/wiki/The_Forever_War

The novel is widely perceived to be a portrayal of the author's military service during the Vietnam War, and has been called an account of his war experiences written through a 'space opera' filter. Other hints of the autobiographical nature of the work are the protagonist's surname, 'Mandella', which is a near-anagram of the author's surname, as well as the name of the lead female character, Marygay Potter, which is nearly identical to Haldeman's wife's maiden name. Importantly, if one accepts this reading of the book, the alienation experienced by the soldiers on returning to Earth – here caused by the time dilation effect – becomes a clear metaphor for the reception given to US troops returning to America from Vietnam, including the way in which the war ultimately proves useless and its result meaningless. He also subverts typical space opera clichés (such as the heroic soldier influencing battles through individual acts) and "demonstrates how absurd many of the old clichés look to someone who had seen real combat duty."