In the December 7, 2012, issue of the New York Times, David Kopel wrote an opinion piece about the recent U.N. treaty that was not ratified by the United States senate. If you missed it, the treaty concerned persons with disabilities but there were some areas that bureacrats with the United Nations would fill in the details later--at least that was my understanding.
Recently there was a video of Anderson Cooper grilling Senator Mike Lee (R-UT) on the failure of the senate to ratify the treaty. This opinion piece would have been helpful to support Senator Lee's position.
There are several treaties expected to come before the senate in the coming months including the arms treaty. David Kopel mentions that as well.