It's true that each culture has its own strenghts and weaknesses. But you raise some very interesting points and I can't quite get them out of my head. Does this phenomenon turn up in other countries? Other countries allow gun possession, ie Canada, Switzerland. Is this a peculiarly American tragedy?

Seems to be. And if so, I think you are right, we must look deeper than gun ownership and violent imagery though both may facilitate a problem that's latent. Does it begin in that whole 'Death of a Salesman' dream?