SB,
I'm going to disagree with you on this one. Yes, it is a bit of a headache to keep track of numerous different countries. But, my emphasis is on profiting from the PM bull. I don't know for sure if Mexico is a safe bet. Nor Argentina, Peru, China, Canada, or even the US. But, if the majority of them remain sound, I will do well.
Deverisifcation can be de-worse-ification, but I think that is true when you are in too many asset classes and too many sectors within each class.
I've chosen to specialize in Commodities with a focus on PM and energy shares, primarily in producers with cash flow and upside and a few explorers. Within that sector, it seems prudent to diversify geographically as well as spread the company-specific risk. This just seems like prudent risk management to me.
Be in the right sector(s) and pick the ones with best potential and good risk-reward profiles.
Regards,
CD