This book was published in 1999 and nominally takes place starting in 2004. As might be expected with this timeline, many of the details were overtaken by events: in addition to the Iraq and Afghanistan wars, the author refers to the then unknown causes of the crashes of TWA Flight 800 (spark in an empty fuel tank that caused an explosion) and USAir Flight 427 (taken down by a rudder jackscrew problem that was extremely difficult to diagnose.) Since the plot revolves around terrorism, this is significant and should be born in mind when making a decision to read it.
A major part of the techno-thriller genre is its attention to details. Tom Clancy famously caused investigations into the details of his books because they regularly revealed things that military people thought were secret. While I'm willing to make allowances for things the author couldn't have known, there are many details that the author both could and should have known. A few of the major things that broke my suspension of disbelief:
* The KC-135 is closely related to the Boeing 707, not the "military version of the DC-10".
* The 'U'-class submarines are not the only diesel-electric submarines that the UK has ever built. In fact (virtually?) every submarine in WWI and WWII was a diesel-electric design. The major advantage of modern diesel-electric subs is that they can react their diesel fuel without conventional combustion, so don't need to surface to run the diesel.
* "Air Force 1" is a call sign, not an airplane. It is used by any USAF aircraft carrying the president of the US. Similarly, "Air Force 2" is the call sign of an aircraft carrying the Vice President but not the President. There is no such thing as "Air Force 3".
* Adding a very large openable pressure compartment with sensitive electronics outside the pressure hull of a submarine (a major plot point) would be extraordinarily difficult. The increased buoyancy would be very difficult to handle without fundamental re-engineering. Further, any such compartment would be very difficult to add while maintaining the navigation properties, and even more the quietness, of a sub.
* Any even vaguely competent passive sonar operator would be completely unable to miss the sound of a RHIB crossing the surface nearby.
According to the author, his technical advisor was Adm. Sandy Woodward (of Falkland Islands War fame). I don't see much excuse for missing these sorts of details.
Leaving aside the technical issues, the protagonist of this book is the principle terrorist involved in the plot. He is the primary focus character and the primary viewpoint character throughout. While there might be a place for such a book, it was not at all what I was expecting from previous books in the series.
And the ending of the book was deeply disappointing in pretty much every way. I won't say more for fear of spoiling the book, but it was both contrived and incompatible with the character of the protagonist as it had been established previously (including in this book.)
In an interview at the end of the audiobook, the author claims not to write multiple drafts of his books. The author should really have written a second draft of this book.
The chapter-by-chapter writing here is good enough to keep this from getting a rating of '1'. but there are enough other issues to keep me from rating this any better than '2'. This is a very sad continuation to a series that started quite well. Unfortunately for me, I purchased both this book and its sequel at the same time, but that may end up being just a sunk cost. At this time, I have no interest in reading any more in this series.