this is the highly subjective way I read and interpret literature
(the emphasis lies on literature, so you'll only find a couply of trashy readings here and there)
As the last one of the Forever "trilogy" Forever Peace is not really a sequel nor a prequel but in some way it is still related to The Forever War and Forever Free since it is taking place in more or less the same universe as those two, so I’m going to call it a spin off, although it is not really one of those either.
Instead of an intergalactic war in time and space, humans are fighting their own battles against each other in this novel. This time, you follow along the protagonist Julian, an increasingly depressed soldier with a pacifistic conviction and a suicidal tendency, who is thrown into what reads like a very Vietnam-ish scenario. I enjoyed the story, it has a good concept, there were some nice and unexpected twists and turns, yet it was too lengthy. After a good, but already extended first half, the story slowed down almost to a point of redundancy, and shortly after it had slightly picked up the pace again, everything was suddenly crammed into the last 5 pages.
Furthermore, Haldeman is constantly alternating between first and third person narration, switching back and forth after each chapter. Since the chapters are quite short (around 1 - 3 pages) the perspective shifts quite a lot. You get used to it, but most of the time it is unnecessary and hence a bit annoying. Other than that, Haldeman has a fluid and entertaining writing style and seems to be getting increasingly fond of using punchlines to conclude a chapter. It was quite funny and cute the first couple of times, but is very much overused in Forever Peace.
While reading I had so many Pacific Rim and Avatar flashbacks, that I wonder if some of the script writers of those movies are secretly some hardcore Haldeman fans.