Declare is a intense cold war spy novel. Complete with spies that are top-secret amongst the standard spies, sexy foreign spies, renegade double-agent spies, and my favorite: spies playing high stakes poker games.
It is also speculative historical fiction. What does that mean? In this context it means that almost all of the characters actually existed and that Tim Powers did a hell of a job researching this to within an inch of its life to make sure that the timeline was plausible with real world events. I didn't realize this while I was reading it. It made the postscript a complete mindblower.
While it doesn't jump along with the action of a James Bond Thriller, it does keep the interest by scrambling the lines of reality. The first part is complete real world, "indoctrinate the new spy" prose. But part 2 finds us atop Mount Ararat confronting djinn and in The Empty Quater meeting ancient Sumerian kings. This constant jumping back and forth does leave the reader wondering where things are going. All in all I would say this is a good read for people who aren't sure they like the fantastical elements of fantasy and sci-fi but are curious about the field. Also, a good read for spy novel lovers and historical fiction fans.