So, what if there are dozens of other-companies making electronic components (not arms) which eventually find their way into missles, control systems, engines, electronics of war planes, tanks, radar systems, Pilatus aircraft, etc. The example of Pilatus is a good one - I am sure it supports a massive support industry, as any other.

What if some of these systems, if this is they way warfare is going, is using Microsoft Windows as operating system? Will we restrict these businesses as well? Where does it end?