The Telegraph reports that North Korea has responded to threats of sanctions by declaring that any attempt to impose sanctions will constitute an "act of war".
A bit of a slap in the face for the supranationalists. Sanctions are, of course, the last resort of the peace-at-all-costs types who place such faith in the UN and "international law". These people believe that there isn't anything that can not be sorted by applying diplomatic pressure backed up with sanctions - even though such a policy has failed time and time again. A sort of "if it is broke, don't fix it" approach.
Unfortunately, for the advocates of this approach, North Korea has got it's shot in first. Apply sanctions and we'll respond with "a series of physical corresponding measures" said it's Foreign Ministry. Which is diplomatic speak for "we'll shoot first and answer questions later".
So, what now for the internationalists? Over the last few years, this particular model of international diplomacy has looked increasingly impotent. Sudan, Iraq, Iran and North Korea have all challenged "international law" and found it about as durable as a Labour party manifesto pledge.
Law has, at the very least, three basic requirements.
1) The willing agreement of the people to accept it as a legitimate restraint.
2) An accepted and recognised judiciary to implement the law and pass judgement.
3) A police force (not a service!) which is capable and willing to uphold the law by the use of force if necessary.
International law does not have any of these which is why it is useless. The UN is, therefore, useless.