Sure we all agree that North Korea has a democratic right and freedom to live isolated from the rest of the world in isolation and in communism, BUT it 'd be naive not to feel worried about her nuclear arms. Japan for one is a recognized demilitarized state, that has no army and will never have one, Japan's integrity deserves to be respected. Now Japan surely feels threatened. I can only imagine how panicked the Japanese people must feel today and how fearful they feel about living in the shade of a nuclear power that is playing with fire. Try to put yourself into the Japanese's shoes. - Secondly if North Korea and Iran start a nuclear co-operation and an exchange of know-how and materials, then indeed our Planet and all mankind will be in a very grave danger.
from the article: Israel urges 'swift' world response to North Korea nuclear test