I think my thoughts about this book were best expressed in a text I sent to a friend: this is like Stephen King wrote a Dean Koontz novel.

It's definitely more sci-fi than horror, which is my favorite subgenre of King stories, and there's a political/anti-war theme that runs through the book that was written pretty well: King thinks drone strikes suck (and he's right) and isn't a fan of youth being stolen by the military for endless wars. The justification for those "drone strikes" (which becomes a play on words later in the book) is shakey and based on questionable intelligence. The people who run The Institute are mostly veterans and former law enforcement, and they engage in barbaric tactics both "on the battlefield" (aka inside a child Gitmo) and when recruiting new soldiers. Those child soldiers are lied to, emptied out, and discarded once they aren't useful anymore.

Very cool job weaving all that in with the narrative, interesting wordplay, and a fun thriller story. The only place it lacks, honestly, is with the mostly typical King ending. The last few chapters were a bit info-dumpy and clearly there to answer the unanswered question of "why", but the ride there was fun and kept me into it.

The series will be interesting to watch, just because I wonder how many of the showrunners really picked up on the underlying themes of the book.

Tl;Dr: it's "Scanners" but as an allegory for the military industrial complex and the war on terror.