Barkley, I generally like what you write, but I think you screwed up this one. Between-country comparisons are even more suspect than between-state comparison because the ceteris paribus condition is very difficult to meet, hence the attribution of causality is moot.
I think the main problem with the guns-prevent-violence drivel (and I really think it is a textbook example of hogwash) lies in small-number comparisons: the incidence of defensive gun use is so low, that even a single instance can significantly alter the rate. I suspect our friend jordan may object to those low incidence rates, but claiming high rights would put everything we know about criminal behavior on its head. It just ain't so.
Wojtek