I found this book extremely interesting although sometimes it was quite heavy going. The book looks at how the idea of a perfect world/state developed as an unachievable ideal, and how the attempts to realise it in later times have caused so much suffering and pain in the world but have achieved so little. Whether communism, Nazism or the current American Christian model of a world of democratic capitalist nations all attempts to remodel the world have ended in disaster.
This utopian thinking has a resonance for all of us, I think. It's easy to believe we can reach a state of perfection in our personal or professional lives where we will be happy and live in harmony, but our very natures make this impossible. We are always reaching for something - it's human nature - utopia for ourselves and for society as a whole is unachievable and we would do better to take a more pragmatic approach to the world's problems.
The other thing I got from this book was the idea that human beings are not rational creatures, nor are we going to become so in the future. We will always fight, compete, envy and believe in things we cannot possibly know. That is what it is to be human. Most of the decisions/beliefs of most of the people of the world are made and held because of emotion, belief, culture and the influence of others; not through rational analysis. There is no point attempting to develop conceptions of a better world that do not take this into account at their very core.
On the down side, this book was heavy going at times, and a little too focused on the recent Iraq war later on in the book. However, I'd certainly recommend it.