From the AP:
UNITED NATIONS (AP) — American officials say Secretary of State John Kerry will sign a landmark treaty regulating the multibillion-dollar global arms trade during the annual United Nations General Assembly meeting this week.
The officials said Kerry will sign the Arms Trade Treaty on Wednesday, initiating an uncertain ratification process in the U.S. Senate. Some lawmakers have expressed strong opposition to the United States becoming a party to the treaty. The officials spoke on condition of anonymity because they were not authorized to be identified as the source of information about Kerry's plans.
The U.S. is the world's largest arms dealer and its accession is seen as critical to the treaty's success, although many of the world's other top arms exporters and importers have not signed the document.
I guess he's considers himself safe from unintended consequences.