An estimated $800 billion in damage was caused Monday when a horde of bloodthirsty Mongols sacked and pillaged the U.S. The horse-mounted Mongol warriors, operating from a stronghold in the Canadian wilderness, moved in from the north and plundered U.S. riches, sweeping as far south as Oklahoma before making their way back across the border. President Clinton is calling for the construction of a national moat to prevent future attacks.