Thank you for all of the comments. Would it help if I told you the definition of empire we are working with in the class? (You can critique the definition, with pleasure, but we needed something with which to work...)

"Empire is an agglomeration of multiple polities and diverse populations bound together in an uneven relationship in which one polity exercises significant control over the others and, in many cases, claims sole sovereignty over all of the polities. This relationship is characterized by an intricate network of political, economic, cultural, legal, communication, and demographic ties. An empire is born when disparate polities or peoples becomes suborned to a dominant polity. It can be said to have ceased to exist when the constituent polities re-establish sovereignty over themselves or become so integrated into the dominant polity that there is no longer any significant difference between them either by law or in practice. In many cases, however, one empire segues into another, a process that is denoted by the transfer of the imperial metropole to a new location."

What I will be asking students is whether the U.S., China, or Russia fit this definition TODAY. However, I don't want to restrict y'all from also answering the question within the context of your own definitions of empire, if you prefer.

I recently attended a great class at the university of Oslo called: America and the world since 1898. Basically, it adressed US foreign relations in an a historical perspective. The question if U.S foreign involvement could be defined as imperialism was heavily discussed, and the subject of our final paper. One of the authors we read was Stephen G. Rabe which had, in my opinion, a pretty solid definition of empire, originally put forth by another historian. It read as follows:

The key to imperialism is power - the power to make others move as the imperial state dictates. As the british historian Tony Smith has noted, imperialism exists when a weaker people cannot act with respect to what it regards as fundamental domestic or foreign concerns for fear of foreign reprisials. Imperialsim can take several forms, both formal (annexation, colonialism, or military occupation) and informal (economic penetration, political subversion, or the threat of intervention).

If one uses this as tool to define empire, I´d say labeling the U.S, China, and Russia as empires is pretty accurate.

EDIT: I linked this in a comment below, as well. It's very salient to the topic. It's a bit semantic for my taste, but worth at least a cursory read.

Are you asking about nations which now exist being classified as empires?

I think the biggest issue right off the bat is trying to debate the presence of an autarch or other authoritarian structures. Empires, in general, have Emperors. The generally accepted Empires all had either tyrants or extreme top-heavy governments. The British Empire, I would think, probably had the least potent central figure, but the role of the aristocracy in determining and executing policy was central.

EDIT2: Please notice I'm not excluding governments with strong central power which were not ruled by single individuals.

American elections are free according to all the information available to us, and our executive changes quite frequently. One might argue the Congress' long terms may constitute an aristocracy, but maybe not an autocratic one.

Russia, particularly, gets a reputation for autocracy but I'm not a current affairs expert and I couldn't say whether its deserved or a Western news trope. There's also the flip side, where Putin has a bit of a personality cult in some segment of the population - if he is popularly elected, then it's hard to say he's a dictator. However, something often brought up about successful empires is the inclusion of other cultures, which the Russia Empire even when it called itself such did not do, with the stunning example of Chechnya.

The shift to capitalism in China is near the 20-year-rule line, is there anyone who can talk briefly about that, and the way it affected centralization of power? I know terribly little about the structure of the PRC.

In opening discussions of comparative empire, we often start with chapters from Jürgen Österhammel's Colonialism: A Theoretical Overview. He identifies various sorts of colonial relationships--which exist as components of any idea of "empire"--and which stretch from the ancient world to the present. We may disagree with his particular choices, but it offers a place to start.

I'm going to need a little bit more detail about the question you are asking before I can attempt an answer.

I'm trying to think about this in terms of the medieval HRE, which is what I'm most familiar with. Of course, the old saw goes that it was neither holy, nor Roman, nor an empire (the medievals definitely thought it was holy, though!). But they defined themselves as an empire, and defined themselves as the successors of Rome. What they thought about themselves is more useful to me historically than whether they were really an empire or not.

I feel like "empire" is such a constructed term that a historian applying it to an area/state/entity/people that didn't apply it to itself is a little tricky. And I think it gets extra tricky, and very politically touchy, when you're trying to argue it out in a modern context. I mean, Americans do not think of themselves as establishing an empire, and I could see a lot of them being insulted by the idea that they are ("who you callin' an imperialist?" (sub-sub-point, to be honest, I'm a little insulted by that, and I'm not a 'murica, fuck yeah! type)).

Certainly you can, and people have, made the argument that we constitute an economic empire. But there are a lot of Americans who are actually getting the very short end of the economic empire stick, and who would be super happy if globalization reversed itself, and they could have their factory jobs back.

Then there's the invasion of various countries. I really reject the idea that it's imperialism. We could probably argue that out (and I definitely think Iraq was stupid, and Afghanistan more justified but equally stupid). But neither country is really in any sort of imperial/colonial relationship to us right now, and there was actually the clear, stated intent to build them into free and independent nations.

I imagine that Chinese and Russian people would be insulted by the implication as well, for different reasons.

Edit: I would agree with /u/whereistheborder that the late 19th, early 20th century expansion into places like the Philippines definitely was pretty classic late 19th/early 20th century Imperialism. But I'm under that impression that what you're asking about is the contemporary US v. historical examples of imperialism?