They are not subject to jurisdiction, where the hell did you get that idea? If a diplomat does something that would be a crime in the US, they are _asked_ to leave via diplomatic channels. They usually leave on their own. If they were under US jurisdiction, they could be TRIED in the US, but that basically never happens. The only few exceptions you will find to this were either cases where a) the person was not really immune to begin with b) their country waived the immunity or c) the immunity lapsed because the person did not leave the country in a reasonable timeframe after being asked to