Twenty-first-century citizens of the United States exist in a state of “imperial denial.”

Photograph by Tim Cragg.

That is correct. Despite the fact that the United States is clearly playing a role comparable with that of past empires, Americans and their political leaders insist that the United States is not—has never been—an empire. I would define this condition as imperial denial.

Our global power differs fundamentally from that of previous imperial powers such as Great Britain and Rome.

I disagree. All great empires, including these three, have projected their power economically and culturally, as well as militarily and politically. The mere fact that the United States does not lay claim to vast swaths of territory for very long periods of time does not make it any less an empire. In any case, controlling large areas of territory is much less necessary in the 21st century than it was in the past, thanks to huge advances in military and communication technology.

Empires are a natural consequence of the accumulation of national wealth.

It is, of course, possible to be wealthy without acquiring an empire. Think of the history of Japan or West Germany after 1945. There needs to be some reason for expanding politically and militarily other than wealth alone. And, of course, it is worth remembering that Japan and West Germany became much wealthier after they had abandoned their dreams of empire. Empires very often come into existence out of a combination of insecurity—that is to say expansion driven by the search for greater security—and also some kind of cultural sense of mission. The Bush administration had a very clear sense of its mission to democratize the world, beginning with the Middle East. Victorians were convinced that it was their mission to civilize the world, beginning in darkest Africa. So I would suggest that a combination of insecurity and almost messianic sense of purpose is generally the reason for imperial expansion.

Liberal imperialism is a positive force for change.

Liberal imperialism can be a good thing. It sounds like a paradox, especially to Americans who imagine that liberals can never be imperialists. But it is not paradoxical, really, because in the early 19th century, when the term was coined, it was clear to a whole generation of liberals that if they seriously wanted to improve the lot of people in backward economies, some form of intervention to produce better governance was necessary. I think liberal imperialism is essentially about imposing better political institutions on parts of the world that are incapable of acquiring those institutions themselves. So, it is not a paradox, but, of course, it is not always a good thing. It can be a good thing if it is carried out successfully, and if the altruistic objective, which is so well articulated these days by British Prime Minister Tony Blair, is actually pursued consistently.

The trouble with liberal imperialism—and this was true a century ago, as well—is that power corrupts. It can corrupt even quite lowly functionaries in the imperial force. It is quite hard at the sharp end, if you like, to remember those altruistic objectives with which your leaders began. The events that occurred at the Abu Ghraib prison rather nicely illustrate the way in which low-level functionaries in an empire can be corrupted by power, even if the objectives that sent them to a country were really quite altruistic.

The United States’ imperium is more cultural than economic.

It is very hard to separate these two things, because America’s cultural reach—the expansion of its extraordinary combination of dietary, sartorial, musical, cinematic and other trademarks—is largely the achievement of the American corporations. When people speak of Americanization—and they often do speak of it in a negative sense in Europe—what they are usually talking about is the growing influence of the American corporation, be it McDonald’s or Wal-Mart. America’s cultural expansion is a function of its economic expansion.