sharp new warning of all-out war. For the first time, the mysterious and secretive nation has threatened a preemptive nuclear strike against the u.S. It comes at the u.N. Approved tough new sanctions.... See More
sharp new warning of all-out war. For the first time, the mysterious and secretive nation has threatened a preemptive nuclear strike against the u.S. It comes at the u.N. Approved tough new sanctions. So, how dangerous is the situation? What counter measures could america take? Here's abc's chief global affairs correspondent martha raddatz. Reporter: Thousands upon thousands of north koreans rallied today around a north korean general delivering that stunning threat, a first strike nuclear attack with a vow to engulf washington, d.C. In a sea of fire. Threatening a nuclear p preemptive attack. Never done that before. Reporter: The north korean dictator lashing out against the u.S. And south korean military exercises and today's new, stiff, u.N. Sanctions. Analysts say north korea is still years away from perfecting a nuclear weapon, but they are getting closer all the time. The threat of a preemptive strike on the united states, even if that is not possible now, is terrifying. You have to take this seriously. Reporter: North korea does not yet have a missileapable of hitting the continental u.S. But america has satellites in space, radars atea and and the ground, designed to detect a missile launch. Dozens of intercepting missiles could be fired from california or alaska to take out enemy missiles, even nuclear ones, before they reach america. But the system is far from foolproof. However, the most immediate threat tonight from north korea is far more conventional. They could fire on south korea, america's ally, like they've done before. This is how war's start. Threats become maneuvers, are met with retaliation. Pretty soon, you have world war i, or vietnam. Reporter: And there is renewed concern tonight about mobile missile launchers in north korea, which could fire rockets capable of hitti south korea. There is nothing imminent, but these statements have everyone on edge. Diane? All right, martha raddatz, thank you so much.
This transcript has been automatically generated and may not be 100% accurate.