Josef certainly likes to live undeath in style and it's easy to imagine him hob-nobbing with a lot of famous/rich/influential people over the centuries. I know it sometimes can seem like a contrived plot device to have the immortal vampire knowing all the historical figures, but in Josef's case it really does fit and not outside realm of possibility imho.
I've always seen him coming to America fairly early because he foresaw getting in on the ground floor of a wonderful business opportunity, a New World just starting out, ripe for investing/exploiting, etc. (not that he wouldn't have gone back and forth over the centuries, of course). I see him as having gotten into the stock market at it's beginnings, with San Francisco and the Mining business. Of course he's so good at it, he practially invented it!
What the heck could he have been doing in Afghanistan do you think? Any ideas?