After years of mutual resentment and tension, there is a sudden recognition that the real interests of America and its allies are diverging sharply and that the transatlantic relationship itself has changed, possibly irreversibly. Europe sees the United States as high-handed, unilateralist, and recklessly belligerent; the United States sees Europe as spent, unserious and weak. The anger and mistrust on both sides are hardening into incomprehension.

In the influential journal Policy Review, the heavyweight commentator Robert Kagan analysed this impasse so incisively that each side was able to see themselves through the eyes of the other. Tracing the widely differing histories of America and Europe since the end of the Second World War, Kagan makes clear how Europe's need to escape a bloody past has led to a new set of beliefs about conflict, power and threat, while at the same time, the United States has evolved into the guarantor of the European order by dint of its might and global reach. This remarkable analysis is already being discussed by governments from Washington to Tokyo. It is essential reading.