Peaceniks in Seattle of various stripes withstanding, there's a case to be made that we have as much peace as we do from foreign attacks not merely because of our geographically favorable position but also because, lest we somehow magically forget, we're sitting on a stockpile of nuclear weapons that have had a historically (and necessarily terrifying) preventative role. Knowing that if the U.S. wanted to it could effectively transform large swaths of the world into a toxic radioactive sea of ash is a strong disincentive.
Now, sure, at the 50th anniversary of Star Trek Americans don't want to imagine that the kind of liberalism prized in an entity like the Federation (i.e. America centuries from now if we're really honest with our pop culture selves) depends on the ability to tear things apart at a subatomic/atomic level (transporter technology, anyone? Does it stop being playing with atoms just because in Star Trek they put people back together?). But now that the Cold War is over and a certain franchise is half a century old we should perhaps not kid ourselves as to the necessity of an idealistic, utopian view of pax Americana within the Cold War polemics being central to the franchise. There's a potential case to be made that there's artistically less reason to buy into the Star Trek utopian franchise now than ever before.