I don't understand what the author's intent is for this article. Is he trying to show how irrelevant the UN is? Or perhaps to say that once a treaty is signed it cannot be amended for all eternity? It's all nonsense.

The law changes to reflect the attitudes, values and beliefs of it's citizens. As a professor you would think he would know that sometimes laws and treaties are not changed until challenged by breaking those laws. 

Moreover, it's exactly this type of thinking that stifles progress; a small minded view which as kept us neck deep in failed drug policy for decades.