It is indeed the product of its age; America is deeply involved in the Vietnam war, many young men were conscripted, antiwar sentiment were raised due to the involvement of the unintended and unwanted war. You can see those parallels in this novel.
The story circles around a young (and then “very old”) soldier Mandella, who is drafted without his consent, due to the Elite Conscription Act, a law passed to conscript high IQ young men and women to fight extraterrestrials in another system far far away from solar systems. The first time setting is the near future, and then continues to about one thousand years. The military also has overcome the male-female bias. Each draftee is sterilized, eggs and sperms stored in cold storage for later use. The concept of “confraternity” is introduced, where male and female soldiers live in the same quarter. Promiscuity is actually encouraged to strengthen the bond, while exclusive partnership is discouraged because it will create tension and competition.
Since it is decades after the first publishing, I feel that the war issue is about outdated. The strongest part of this novel is not even the war scene. It is the social changes caused by war that is interesting. How the politics changes, the economy booms and collapsed, etc.
Despite the outdated war issue, the gender issue and clash of civilization are still contemporary. The heterosexual vs. homosexual orientation is widely discussed. Imagine when heterosexual became the outlier, while homosexual is the new normality. Imagine that you, being heterosexual is seen as an aberration and everyone wants to cure you. After reading this novel I can sympathized with my LGBT friends.
Clash between cultures (or in this case: species) is also the center theme. Many meaningless wars happened just because we cannot communicate with each other. Once we can understand each other, the war seems to be so puny. And in a long term, all wars might sound so silly. Imagine Japanese people that is portrayed as yellow skin savages that fight the allies. Now all of those image has lost, replaced by the uber-cute techno culture spread by the anime and manga. I can imagine that will also happened to the so-called Islamic terrorist right now. Imagine how would we see them decades from now.
The best part of this novel is the time dilation caused by the near-light-speed travel. It is something that is usually omitted in common space opera. It is just like the issue dealt in the movie “Interstellar”. It is something that should be faced by a star faring civilization.
Overall, a solid 4 stars. If Haldeman makes a more interesting war scene, I will give it a 5 stars.