The Forever War is a military science fiction novel written by Joe Haldeman. It follows the story of William Mandella, a soldier who is sent to fight in an interstellar war against an alien species known as the Taurans. Due to the effects of time dilation, Mandella experiences time differently than those on Earth, leading to a sense of displacement and alienation. The Forever War explores the psychological and emotional toll of war. It is a powerful and thought-provoking book that challenges traditional notions of space war science fiction.