Geography made the Pearl Harbor Naval Station, on the Hawaiian island of Oahu, nearly impervious to sneak attack—until the age of the aircraft carrier. “Pearl Harbor is susceptible of being made into another Gibraltar, where the largest fleet may safely lie and where repairs may be made at leisure,” wrote U.S. Senator George C. Perkins in the April 1908 NATIONAL GEOGRAPHIC magazine. “It is completely land-locked, preventing surprise attack from submarines and torpedo boats, as well as from hostile fleets. ...Too much stress cannot be given to the fact that if Pearl Harbor is to be fortified successfully the work must be done in time of peace. When war comes it would be too late, and woe to us if we are not prepared for defense as well as for attack.”