>> so we're waiting for this i think the isotopic signature to totally know what this was. bottom line, based upon what you know, do you think this is real or a hoax? >> we overall would tend to agree with the white house. for the moment, we don't believe that -- we believe north korea is actually possibly bluffing about having an h-bomb. and the reason for that is simple. when we're talking about h-bombs, we commonly refer to a very specific type of nuclear weapon. we're referring to a two-stage fission if fusion nuclear device, which is a device very complicated to build and at the same time the yield associated with that test that happened this morning is a lot lower than the yield you would expect from the testing of this type of weapon. so the testing of a two-stage fission/fusion nuclear weapon. at the same time, though, we have two possible alternatives. yes, north korea may be bluffing. however, they may have undertaken a test of a device that they've already tested before so we're talking about a