Eighty-four years ago today, on December 7, 1941, “a day that will live in infamy,” the United States was attacked by the naval and air forces of Imperial Japan—an event that plunged our nation into World War II.  It’s often been said that America was “lucky” none of its aircraft carriers were in Pearl Harbor that morning.  At the time, the U.S. Navy had seven fleet carriers: Lexington, Saratoga, Ranger, Yorktown, Enterprise, Wasp, and Hornet.  Of these, Enterprise and Lexington were operating in Hawaiian waters.  But in truth, the odds of finding them in port that Sunday were slim.

Why Carriers Rarely Stayed in Pearl

Unlike San Diego or Puget Sound, Pearl Harbor wasn’t designed as a primary carrier base. It was congested, relatively shallow, and not well suited for handling the Navy’s largest ships.  When a carrier entered to refuel or resupply, the Navy moved it in and out quickly to avoid logjams.  If a carrier needed a longer stay, it returned to San Diego, its true home port. To avoid two carriers arriving at once, the Navy kept them on a rotating schedule. That meant the chance of both being in Pearl at the same time was very low—and in fact, most of the time neither was present.  The Japanese understood this.  Their plan aimed to cripple the Pacific Fleet battleships, which were lined up in neat rows along Battleship Row.   Finding carriers in harbor would have been a bonus, but it wasn’t part of the expected outcome.

A Lesson Ignored

The Pearl Harbor attack was bold, but not entirely original. The Japanese drew lessons from the British carrier strike on the Italian fleet at Taranto in November 1940.  They also mirrored—almost exactly—a U.S. Navy exercise carried out nearly a decade earlier.

On February 7, 1932, during annual Pacific Fleet war games, Rear Admiral Harry Yarnell commanded the “aggressor” forces.  Naval doctrine at the time was battleship-centric: carriers were considered auxiliaries.  Yarnell, one of the few believers in aviation’s potential, chose to rewrite the script.

Leaving his battleships behind off the California coast, he advanced with just two carriers and their escorts. Using storm fronts for concealment and maintaining radio silence, he brought his force to Hawaii undetected.

At dawn on Sunday, February 7, Yarnell launched his aircraft from northwest of Oahu. His planes swung around the island and attacked from the west with the rising sun at their backs. Using flour bags as bombs, they “disabled” the airfields and “sank” the battleships at anchor.  The surprise was complete.  Navy umpires awarded Yarnell’s forces a total victory.

Lessons Dismissed

Yet the exercise was not celebrated.  Senior Army and Navy leaders complained that Yarnell had “cheated” by attacking on a Sunday morning, when the fleet was relaxed.  Under pressure, the umpires reversed their ruling.  Officially, the exercise was dismissed as unrealistic.  But abroad, others were paying attention.

History Repeats

Eight years and ten months later, the Japanese fleet approached Hawaii under storm cover—just as Yarnell had.  On a Sunday morning, they launched their planes east of Oahu, looped south, and came in with the sun at their backs.  They hit airfields and battleships exactly as Yarnell had demonstrated.  This time, the bombs were real.  The surprise was total, America’s entry into World War II was sealed and Yarnell was vindicated.