North Korea refused to renounce nuclear energy

North Korea refused to renounce nuclear energy and demand collateral to do so.  I think that North Korea's diplomatic skills are high.  They don't have enough economic power nor political power, so they use military power and deal diplomatic negotiations.  Although Japan have enough economic power, Japanese diplomatic skills are not high, so Japan can't have enough chance to negotiate with North Korea.  Please don't misunderstand me.  I don't mean that North Korea is good and Japan is bad.  Japan don't have enough diplomatic skill, so Japan should develop it and negotiate with North Korea.  Japan should not just criticise North Korea but reflect on a part of themselves.  Without this, Japan will not have the advantage over North Korea.