Davis has written many books and articles, and many have the same theme; however, I am always a little dubious about the "prolific" authors.
The Cause Lost is now available in paperback (hardback might still be available from Military Book Club). Originally released in 1996.
Some authors are so prolific, they only prove they are wordsmiths who could not possibly have fact-checked all that they wrote.
Somewhat analogous is what Ann Coulter described in her book Treason, at page 96:
Flip through any book about McCarthy and notice the footnotes. It is an aresting fact that the supporting documentation rarely consists of primary source material. Academics cite other academics, who cite other academics, with nearly all statements about McCarthy eventually tracing their way back to contemporaneous news accounts from a rabidly anti-McCarthy press. Doing original research on McCarthy is apparently not tenure-track material at American universities. As the saying goes, the first draft of history is written by journalists. And we know who they are. They told us Clinton was only counseling Monica.