I read this book while I was serving in the US Army Infantry in 1993, and it stuck with me, considering the premise, which is that America is going through a civil war between fascists on one side and communists on the other. By this point, I hadn't read 1984, or really, any dystopian future book, so it struck me as grim, and disheartening. Later, I realized that it was good example of the genre (after reading 1984, The Road, The Electric Church, Brave New World, Crake and Oryx, and The Passage), and looked for it to read again. It took me months to track it down, and now that I have, I'm getting it again! Yay! I recommend it if you like dystopian novels.
Update: I finished rereading this after over two decades, and I have to say it holds up well, I think. It was a lot more bleak than I remember, since it really seems like the end of times for America. Also, the proposed last battle and the plans surrounding it seem a little more simplistic than I remember. However, Shaman's journey from SE Asia, to DC, to an insane asylum, to New York, and infiltrating the "enemy," that was a joy to read. And the end, that gave me shivers. I heartily recommend it to fans of the dystopian genre.
I think I was expecting more of an action-centric book. There were a lot of internal monologues and stream-of-consciousness ramblings on the part of the main character which interrupted the flow of the story. Frankly, I didn't think much of the ending either. Not a bad read, but not particularly good.