The one American exceptionalism I would rather do without
Bill Whittle has a good commentary on American Exceptionalism.
Yes, we are an exceptional country. There has never been an "empire" like us. There has never been a country with the power to completely dominate the world with no one to oppose it with comparable might that spent so much of its own resources defending and feeding others. The Athenian empire certainly wasn't that (it took tributes from member states to support its navy, not the other way around), Roman empire wasn't that, and even the comparably benevolent (see: Commonwealth of Nations) British empire wasn't that. Aside from the fact that we have troops and bases around the world, there is nothing about America which is like any other empire that existed in history.
However, this is one American exceptionalism that I would rather do without. While it sounds virtuous of us to feed the poor and help rebuild the countries we defeated (and they were the aggressors in the first place!), it is economically, and morally, unsound.
We held the temporary advantage after WWII and after Cold War, and we used that advantage "for the greater good". Any particular edge, whether it be resource or technology, is always fleeting. While the natural resources of this country is still formidable, it cannot be said that this gives us an edge over all other countries (case in point: we are net oil importer, and even with full development of offshore reserves and Alaskan oil and natural gas, it's likely to stay that way for decades). Technology and knowledge have the habit of getting spread around over time, and unless we continue to innovate, the technological advantage we have right now will dwindle with time.
With these historical, temporary advantage dissipating, I don't think America can afford to be so generous to its allies and enemies any more. America needs to look out for America. American troops should be used for defending American borders and that only (and limited allied interests, when such operations can be proven to be beneficial to our long term interest). And we should let free trade and voluntary, civilian charity replace (or not) whatever "foreign aid" we are sending to African countries to prop up their corrupt government (someone made a good argument that foreign aid to defunct countries actually hurt them because the foreign aid makes the rulers less answerable to the people, because, through this foreign government aid, they have a resource independent from the people).
I am glad that we have been and are a generous nation. But we can no longer afford to be that generous—if I am wrong and if we still can, then we should let people decide on that voluntarily and that means no tax dollars for government charity.