Niall Ferguson has been provoking controversy in England for several decades. He first achieved notoriety in 1999 with his book The Pity of War, which suggested that it would have been a good thing if the Germans had been permitted to take over Europe during World War I. Britain, to preserve its empire, should have stayed out. Since then, Ferguson, who grew up in Scotland, has demonstrated remarkable fecundity, emulating A. J. P. Taylor not only in his zest for polemics but also in his productivity. But the criticism of Ferguson has become increasingly pronounced in recent years. It centers on a simple question: was it a good thing for Britian to be an empire in the first place? And, by extension, should America behave like one as well?