In the war against an unknown alien, the battlefield stretches across light years. Conscript William Mandella fights for earth, only to find the planet much changed on his return. 
 The writing style is one that seems common among classic science fiction works - it's very journalistic, appearing dry and even monotone even while it conveys a great deal. And there's certainly a great deal here. 
 In a not-too-subtle retelling of the Vietnam War, Haldeman uses relativistic time dilation to explore the experience of the drafted soldier return to a country he doesn't recognize and that doesn't accept him. There's also a lot there about fighting foreign (alien) cultures, not understanding the enemy, not understanding why the enemy needs to be killed, being compelled by propaganda even while recognizing it as propaganda, etc. In other words, the book is one massive smorgasbord of social commentary. 
 The views on homosexuality are obviously outdated, as are the gender relations. Certainly, the approach to heterosexual sex early on in the novel is downright rape-y. I can chalk some of that up to the age of the novel, and there's enough other stuff going on to carry me through the rest, but it bears saying.