A small book for a vast topic. I found it well worth reading. I got it from the library but may well buy the paperback. As I expected, it doesn't succeed in its attempts to explain things but does succeed in demolishing many of the "explanations" we have seen before.
It's also, not surprisingly, off track when it gets to recent history; "As the 21st century unfolds, nationalism is fast losing ground". It didn't take long for that to change.