You need to do your research before cut and pasting bullshit at face value- This is the same rap the gun grabbers do. This story goes back to 2013 and has been conveniently edited to incite you while offering a total incorrect premise of what happened.
http://www.foxnews.com/politics/2013/09/25/kerry-signs-un-arms-treaty-senators-threaten-to-block-it.
The UN small arms treaty only effects arms sales between nations, and honestly, given fast and furious the government wouldn't have a leg to stand on for firearms sales to foreign powers. Dont believe me? That's cool, go read the treaty, I've read it a few times digging for how they report the numbers for small arms across the globe to refute the bullshit US has half the worlds guns or whatever statistic.