FWIW, it seems the policy specifically cites ITAR. This is a very specific Regulation in the states and affects the sale primarily of current US Military gear and stuff useable by unfriendly nations against US troops like night vision, nuclear proliferation items, etc.

It would also apply, for example, to an M14icon Sage EBR stock or a Trijicon TA01-NSN gun site.

ITAR would not, for example, apply to M1 garand parts.