Finished this last night. It's not a sunshiny tiptoe through the tulips kind of book, but very gripping. Some compelling characters - and not always in a good way. I thought it was kind of an odd choice to make Macklin a Viet Nam vet, but about halfway through the book (or more), they mentioned B. Dalton Booksellers, and I had to go to the publishing info to see that it was published in 1987. How I missed this back then, I'm not sure, because I was reading a lot of this kind of stuff back then (notably the Jerry Ahern series The Survivalist).
Thanks for the recommendation, Steve!