When North Korea tosses out another threat of violence against one of its neighbors or the U.S., it's become routine to describe it as an escalation of Pyongyang's rhetoric.

That description captures the fact that North Korea makes a lot of threats without following through. But is there a point where it's not even appropriate to call new threats an escalation?

On Tuesday, North Korean state media said that the country's military command had ordered its rocket and artillery units to be on "highest alert" to strike bases on the U.S. mainland, Guam, Hawaii and other targets in the Pacific and South Korea.

Such threats, many analysts say, are little more than attempts by the North to draw the U.S. into dialogue with the strongest possible negotiating position, as well as a means to shore up domestic support.

On the surface, of course, they are alarming and they are usually accompanied by photos and video from the North of military drills for extra effect. (Some of these drills are unintentionally comical, however, as North Korea displays its aging military hardware.)