CSM
Senior Member
I think the difference is qualitative. Supplying conventional weapons is one thing, handing out nukes is another.
Nations (including the US) sell things like aircraft, high end air defense systems, submarine technology and most certainly the technology for countries to develop and produce nukes (among other things). Dual use technologies that can be used for other WMD are popular as well. I agree that small arms is one thing but all that other stuff will most certainly show up in the wrong place at the wrong time eventually.