What is the author's tone in Delta Force by Charlie A. Beckwith?

The tone of the book is descriptive. By the end, the readers can see how one thing led to the next, but from the beginning of the book, it isn't clear at all. The author blends a story-telling ability with a hidden element of teaching. There are numerous chapters that in fact very clearly explain how it is that the plan for the Iranian hostage rescue was developed and carried out.