There is no such thing. There are treaties and there is war. This is an act of war, but the UN is not sovereign, so it is the countries who allied in this act of war who are at war. If N Kor does not respond in a warlike manner, they are incapable of making war.
I don't understand this comment. There are an infinite number things besides treaties and war. Countries have varying levels of business with each other. This UN resolution simply imposes sanctions by countries which is not an act of war. So the term "punish" is a correct term for this.