He did say "unless" in his response here is what I got back from them
Thanks very much for getting in touch with me and letting me know what’s on your mind regarding the United Nations Arms Trade Treaty.
A treaty that brings greater transparency to the international trade of arms may indeed be a worthy idea, but not if it undermines the 2nd Amendment or threatens our country’s sovereignty.
On July 22, 2012, I joined Senator Jerry Moran and 46 colleagues in a bipartisan letter to the President and Secretary of State Hillary Clinton saying we will oppose ratification of the treaty unless it explicitly recognizes the legitimacy of lawful activities associated with firearms, including but not limited to the right of self-defense.
I have heard from many Tennesseans who have concerns about this treaty, and I appreciate your taking the time to let me know where you stand. I’ll be sure to keep your comments in mind as issues surrounding this treaty are discussed and debated in Washington and in Tennessee.
Sincerely,
Lamar