http://www.google.com/url?sa=t&rct=j...arddPtKpSO_Tmw This is a pretty informative paper on the issue.
I'm afraid you are wrong. The US is a signatory.Neither is the United States. That doesn't justify what they do to their citizens or what we do to ours. Despite the strict literal definition, it is still murder in my mind. A government's decree doesn't justify the wrongful killing of another. Killing is only justified in self-defense.