Who Are We?

As this week we focused on the question of the existence or non-existence of an American Empire, I figure it is fitting to consider the question in this week's blog post.
When looking at the drivers of empire throughout history, I find the economic theories to be the most convincing. Empires in the ancient world were merely the extensions of states that ended up having to adopt specialized forms of government to control expanded territories. States expanded under the principle of "war made the state, and the state made war," meaning that to maintain its warring capabilities it had to extract wealth from its population, and to extract enough wealth it had to conquer more territory (limited, of course, by the loss-of-strength gradient). Wealth was found in the exploitation of cheap labor (usually pretty easy), arable land, and natural resources. If a state had a low loss-of-strength gradient and found it easy to continue expanding, it did so and maybe in the end accrued an Empire. The preferred methods of wealth extraction varied, and so some empires were based on land and others on sea, some on mercantilism and coercion and some on free trade. However, the common denominator -whether in the Athenian, Roman, or British Empires - was the presence of military arms to ensure the state's wealth extraction.
I find this useful when considering the question of a modern-day American Empire. Do we accompany our wealth extraction capabilites with military strength? If so, how close are the two linked?
America today certainly engages in global wealth extraction. We resemble the maritime free trader far more than the land-based, coercive mercantilist. However, even with the less coervice - but still sometimes imperialist - maritime trader we must draw some significant distinctions. Presently we maintain numerous bases and station thousands of soliders around the world. However, these soldiers are not sanctioned to interfere with their host country's domestic politics or trade regimes and may do so only under extreme circumstances. We no longer need to send citizens and soldiers to occupy a land for its cheap labor - multinational corporations can do this for us unaccompanied by force. Though they move freely around the world, states can still exercise a large degree of control over them. The mercantilist acquisition of resouces and territory has proven too costly to be effective, and free trade has solved the problem of wealth extraction in a far more efficient manner. Free trade requires only stability, and is not necessarily furthered by the presence of military force.
America today has an overriding interest in unrestricted free trade and so has constructed international liberal trade institutions to this end. The use of our force is to ensure the durability of the system, not the extension of our state. I believe this is the key in distinguishing between empire and the limited extension of the power of a dominant state.