I had the pleasure of proofreading this in advance of its publication, and can heartily recommend it to anyone with an interest in drone warfare or military esoterica. I've always thought I was quite well-versed in historical military oddities, but this book introduced me to plenty of episodes that had completely passed me by (Farnhey's 1930s drones, Fire Bees etc.) as well as some truly terrifying tech currently in development. For the record, before reading it I didn't know much about drones specifically, beyond what I'd gathered from watching the news and a bit of Wikipedia. I'm much more well-informed now!
There's a staggering amount of research here, well-sourced, and dispassionately evaluated. For all that, it's an easy and enjoyable read that manages to make the drier, more-technical aspects of the systems interesting and relevant without (ahem) droning on (sorry!). The author takes a well-reasoned and non-judgmental stance when considering the ramifications of these machines and their merits relative to the more-familiar, larger drones we tend to see in the news, but my favourite parts are those which describe the application of biological principles and the behaviour of natural organisms to their development: Simple things, like the coordination of swarming birds, the ability to perch, remote communication between foraging insects and the like, that designers are copying to overcome some of the problems their devices face. The author also makes some compelling arguments for the inevitability of the drones' eventual ubiquity, based on the history of military procurement and fighter development. Again, this is an area that could have been quite dull in the wrong hands, but DH's journalistic experience stands him in good stead, and it's hard to argue with the numbers he cites.
I have no hesitation in recommending Swarm Troopers to anyone who likes gadgets, military history, or aeroplanes, or who just wants to know what to expect from the little sods in the future. And, if you're ordering the paperback version a year or two after publication, and it's being delivered by an Amazon drone...just watch yourself! ;-