[Mugwump]

So very true, I completely agree. I believe that the major point of the story is the "dislocation" of returning home.
The nature of combat is a minor secondary point for readers who like action rather than "what if" scenarios.

Yes. IMO there is a distinct undertone of (understandable) bitterness in the novel. Haldeman is trapped between valuing his Vietnam experiences and cursing them for stealing his former life away from him.

To me The Forever War reads like a cry of anguish above anything else.

It’s a beautifully subtle and complex piece of work, IMO.

[ArthurFrayn]

Haldeman is trapped between valuing his Vietnam experiences and cursing them for stealing his former life away from him.

Again, very well put, and this is key.
Like Joseph Heller, Haldeman feels that through his experience he has earned the right to make an evaluation of his experience whether it is critical or not. He was there, his ass was in the grass -he can say what he wants.
This is does not always go down with ex military who feel it's part of the job to remain silent and supportive of the PTB even after one's tour of duty. Many soldiers feel it is an unquestionable code of conduct to keep quiet about what one went through in combat.
But, to do other than that , is very much a Vietnam era phenomena, and it's one that still has resonance even today. Consider events in the recent US election.