If we can't stop attacks in our own airspace, how can we stop North Korea?

North Korea continues to talk tough as it waves its nukes at the U.S. and the world.

Meantime, we've sent a warship described as a top-of-the-line guided missile destroyer to Japan. If that kind of posturing isn't provocative (particularly considering Bush's reputation as a bring-'em-on bully), what is?

Now, as someone pointed out to me recently, if our military couldn't even intercept some hijacked planes on 9/11, how can we have any confidence in their ability to intercept any North Korean missiles that might be headed our way?