Imperialism is bad for either the imperialist or the conquered.

I too appreciate that your arguments are based primarily on empirical evidence, however some of your foundations are misplaced. I suspect that is more a result of popular misinterpretation of history rather than your own error. The Roman Empire did not fall because it was simply "too large." Contrarily, internal strife was the primary cause of the Roman Empire. A series of civil wars and rebellions, the result of a corrupt, decaying, and decentralised administrative structure rather than national land area, crippled the Roman military, economy, and political structure. Rome decayed on the inside, as a result of poor policy, long before its shear size could contribute to its indefencibility. While internal strife could be connected to size, empirical evidence shows that it is not. Small states frequently suffer from terrible political corruption and internal fracture (take a look at many Latin American states), while the British and American Empires, two of the largest in history, suffered relatively little from internal strife. I wish to address your claims about the overextension of the American Empire, but I shall first address the trade deficit, the debt, and deindustrialization in America because of their importance and the relative simplicity of explaining them. The trade deficit, first and foremost, is a good thing rather than a bad thing. It is the result of deindustrialization, a transfer from the production of material goods (manufactured and agricultural) to services and wealth. Deindustrialization is the result of a population growing so opulent that it no longer has utility for all of the material goods that its wealth can provide, and consequently must endeavour to move its wealth into the production of unnecessary services. While the production of services certainly has less utility than the production of goods, it is not necessarily a bad thing. Rather, our capital can be employed more efficiently by producing wealth and purchasing goods than producing both. The debt, on the other hand, has grown to large to be beneficial to our economy. However, it is the result of mismanagement that could similarly be done in a smaller country (many smaller countries have far larger debts as a percentage of their GDP than does the United States). It likely will not lead to an economic collapse because the capacity of the United States to produce wealth is too great, and (under better management) fiscal discipline and inflation will, over time, eat the debt away. The United States is actually not over-extended, and the poor results we have in our modern strategic were commonly felt by Britain and other global empires. The British, like many other European empires, paid the lion's share for the defence of their possessions. Their troops were sent to all corners of the world, and most were from the British Isles themselves rather than the colonies. This did not result in overextension, but rather allowed for the rapid execution of British policy. The British, like the modern United States, could respond to any global crisis far more rapidly than others. They were consequently able to maintain regional balances of power, and keep the seafaring commerce that was so vital to their survival open. Similarly, the United States keeps a wide array of military bases to keep the global trade routes that supply its industry and market open, because without them it could no longer support itself. The idea, however, that the United States could not defend its far-flung empire in conflict is misguided. The British, in times of crisis (such as WWI and WWII), were able to draw extensively from their colonies to fight their enemies. It is very probable that without their empire, the British would have (at most) stalemated in WWI and lost WWII. Similarly, if the existence or the large-scale stability of the American empire were ever in question, it would be able to draw extensively from nations like Germany, Japan, South Korea, Israel, and its other allies to defend the heartland. As for your contention (implied as a fact) that the United States is an empire, I agree. And with our empire, we have created a sprawling global economy that has enriched the world's third most populous nation to also be amongst the Top 5 wealthiest in per capita income (a feat that could not be accomplished otherwise). It has effectively spread its prized institution, free-market democracy, around the world (and that system is shared by its allies and the next two largest economies, Japan and Germany). Its far-flung military allows it to respond to any threat or disturbance in a matter of hours. I would say that we are not only indisputably an empire, but that we, even more than the British, show just how good imperialism can be.