In other words, they've conducted their third nuclear test. This one much larger than the prior two.
North Korea appears to conduct 3rd nuclear test, officials and experts say - CNN.com
(URGENT) Magnitude 5.1 artificial earthquake detected in N. Korea at 11:58 a.m. | YONHAP NEWS
Does the theory of mutually assured destruction apply when a rogue state is involved?
North Korea appears to conduct 3rd nuclear test, officials and experts say - CNN.com
(URGENT) Magnitude 5.1 artificial earthquake detected in N. Korea at 11:58 a.m. | YONHAP NEWS
Does the theory of mutually assured destruction apply when a rogue state is involved?