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I read this great book a while ago and have not been able to find it since.
It's a space-opera novel involving a society in which a parasitic organism is planted in people who have died, reviving them but they're not the same once revived. I remember that on the back of the book it was advertised with a catchy quote "The dead are dying" because the parasite would eventually die itself as well so it didn't guarantee eternal life.
Not everyone got the parasite, you had to do something special to earn it. It also involved a female politician who was against the process because the life extension process was too heavy a burden on society. It also involved a war hero who underwent some horrendous torture as a POW. He and the politician hook up. The story also pulls in a woman warrior from an all-female society. This is probably enough information for anyone who has read this novel before and can remember the title or even the author would be enough.