A few years ago, I think 4, I read "Countdown to Terror", an expose by then Congressman Curt Weldon. In it, Mr. Weldon (full disclosure, I have met and cooked for Curt, while discussing this book)insinuates that Osama Bin Laden is in Iran, has been for years. Now, DebkaFile says so too. I have no idea how valid the source is, however, it seems to be decent.
Iran scares me almost as much as the North Koreans.