An American fleet of ships steaming northwards through a thick fog. An onstruction appears on the radar screen.
American captain to obstruction: “Steer 20 degrees east, you are directly in our path”
Reply: “You steer 20 degrees west.”
US Captain: “No, you steer 20 degrees east and get out of our way”
Reply: “No, you steer 20 degrees west”.
US Captain: “We are the US Navy, you must get out of our way immediately”
Reply: “We are a lighthouse – your call!”