I have come to a different conclusion on the last part: I live in Germany, a relatively peaceful country that is reluctant to use its military. Yet, there big weapon manufacturers here and they sell what they develop for the German government also abroad. So countries like Saudi Arabia get access to our stuff. Thus, I am fairly certain that almost every weapon system that has been developed in Germany since the second world war has been used to shoot at people in situations that Germany has no control over. Weapon exports from the US and other countries are much the same. When it is built, it will be used. And it won't generally be used by the power that you entrusted with that tech.

The system isn't perfect.

Just refusing to arm your own country and your allies can't be the perfect answer, either.