This book is somewhat different to Bond's previous novels in that it is much more of a standard technothriller. His earlier works were more akin to war simulations, albeit well written and gripping reads at that.
The Enemy Within is not quite so sure-footed. The basic premise is that America is laid to siege by Iranian-sponsored terrorism, this action covering Iran's secret objective. This is all well and good, and is painstakingly set-up for much of the first half of the book. Unfortunately, a number of coincidences are relied upon and the characters by and large are paper-thin and cliched.
The plot is all wrapped up too easily towards the end and the conclusion itself feels very rushed after the fairly sedate pace of the previous 400 pages or so.
After the excellent Cauldron, this is a bit of a disappointment, and only to be read if you are a Larry Bond fan. And to be honest, even that may not be enough.