Read other letters about this article
In response to good points by pantanal and caiubi, this one in particular from caiubi:
"The protection of national security is a simple matter: it concerns the obligation of the state (the government, really) to protect the physical safety of its citizens from destructive attacks...The protection of national "interests," on the other hand, is a fraud and a deception."
I think you would find, as a practical matter, that this distinction is mostly semantics. Many national interests ultimately lead back to national security...I gave the example of the promotion of international human rights as being in our national interest. I think this is in large part because it leads back to our national security - individuals in coutries whose rights are largely protected, and see us (the U.S., but just as easily the U.N., the West, whomever) as potentially a force that has helped protect them, are less likely to be considered an enemy. Others would claim this amorphous "interest" is a theoretical goal only and bears no reflection on our national security. In my view, it all does - particularly when our national security is as dependent as it is on the progress of this amorphous "war on terror", which is basically a worldwide counterinsurgency effort.
In short, my primary goal in the foreign policy community, of which I am questionably a member, is to protect U.S. interests, that is, national security. Other people broadly define other interests as an essential part of national security, and there's the rub. But the community, I think, would unquestionably agree that U.S. needs (security, interests, etc., however they might be defined) are primary, and doesn't that make us an empire by Glenn et al's definition?