Now let's take a closer look at what Sunday's nuclear test means in terms of the progress
North Korea is making in its nuclear program.
For that we are joined by an expert in the field, Professor Suh Kune-yull of Seoul National
University.
Professor Suh, thank you for joining us.
The claim is this: North Korea came out a few hours after and said it tested a thermonuclear
weapon -- a hydrogen bomb -- and called it a "perfect success."
North Korea has made many, many dubious claims about its capabilities over the years.
How can we verify that this was actually an H-bomb and
not just a more powerful fission bomb?
And if it is an H-bomb, what would that mean, practically?
Seismic readings suggest that one of the tunnels used for the test may have collapsed from
the explosion.
What does that say about the "success" of the test -- a very powerful weapon or perhaps
a poorly constructed tunnel?
Another key claim is that this is a weapon that can be fitted onto a missile, possibly
even a medium or short-range one.
How credible
is that?
It's been over ten years since North Korea detonated its first nuclear weapon.
Using the example of the seven or eight other countries with nuclear weapons, what do you
think is the next step, and at this rate where do you
see the North another decade from now?