I find it so difficult to say interesting things about books that I love. Encomiums tend to be a bit dull, and also ring a bit hollow.
So what can I say about this book? It was, to me, very nearly perfect. Beautifully written--not in a showy way, but very elegant. Every word rang true. It is a page-turner, almost a thriller, but it is also, unexpectedly, a novel of ideas. Ideas about war and parenting and love. Sara and Jason felt real to me. I can quibble with some minor aspects of the book--Jason's motivation for entering the military was a little trite, some perspective shifts near the end did not work--but the core is solid.
(I recognize this review is maddeningly vague. I am trying not to spoil anything.)
All I can really ask of a novel is that it sticks with me once it is finished. The best novels enable you to see the world from an entirely new perspective--to me, that is the purpose of fiction. This book did that. Read it.