The period following the American War of Independence was, for the France of Louis XVI, the high water mark of its diplomatic prestige. With France's arch-rival, Britain, humbled by the loss of her main north American colonies and deprived of any significant continental alliances, Louis felt confident that France could at last re-assume its natural role as the economic, political and military leader of Europe. That this did not happen, and if anything France's international prestige sunk even lower, was a bitter pill for its rulers, and one that was to have important ramifications beyond...