Genghis Khan conquerred Persia and Iraq, post islamization. By then the arabs had already invaded and destroyed persia. Genghis Khan's empire did include parts of what is now Pakistan and Afghanistan, and the name Khan is found among Pashtuns, but that does not necessarily imply that every Khan is a decendant of the great Khan. Khan is not a last name for Genghis Khan - it was a title, meaning something like King. In any event, your views are as "racist" as anyone else here - you seem to imply that anyone who breeds with a mongol is a bloodthirsty barbarian. The afghans dont look anything like mongols, which implies the mongol stock in them is really, really negligible. You are no different than people here bashing islam.
Your theory does not explain the arab invasion of persia or persian invasions of Afghanistan or afghan invasions of india. Sorry but 0.005% mongol cannot make someone a mongol...
