Early Warning

On February 1, 1932, the United States began its annual Grand Joint Army and Navy Exercises. As in earlier years, the participating soldiers and sailors were divided into “Blue” and “Black” teams. This year the goal was to test the defenses of the main American bastion in the Pacific. The Blue attackers, with the Navy’s two new carriers, USS Saratoga and Lexington, plus a formidable array of battleships and cruisers, were ordered to land a combined Army-Marine assault force on Oahu, Hawaii.

The Black defenders, equally well supplied with battleships and cruisers and submarines, were supposed to stop them. The Blacks also had imposing batteries of antiaircraft guns and more than 100 planes at their disposal.

For a decade, the Navy had been evolving Plan Orange, which envisioned a war between the United States and Japan. By 1932 the Japanese had the third strongest navy in the world, surpassed only by the United States’s and Great Britain’s. Already, Japan’s diplomats were dropping hints that the country resented the restrictions imposed by the arms-limitation treaties of the 1920s and planned to insist on absolute parity in the upcoming naval talks in London.

The Navy knew surprise attack was one of Japan’s fundamental strategies. The Japanese had begun their war with Russia in 1904 with a devastating strike on Port Arthur that annihilated the Russian Asiatic Fleet.

As the joint exercises got under way, the Blue force sent its two carriers and four destroyers ranging ahead of its battleships and cruisers, under the command of Rear Adm. Harry E. Yarnell. A blunt, salty 57-year-old from Independence, Iowa, Yarnell was one of the few American admirals with an avid interest in airpower. He had learned to fly in the 1920s and had commanded the USS Saratoga when she was launched in 1927. The plans for the Grand Exercises called for the Saratoga and Lexington to make an air attack on Hawaii, but everyone assumed the carriers would be detected and “sunk” by submarines or land-based planes long before they could get close enough—roughly 100 miles—to launch their planes.

Yarnell had other ideas. To evade Black patrol planes, he led his task force to a stretch of ocean, northeast of Oahu, where rain, squally winds, and lowering clouds were abundant in the winter. He also knew that the prevailing northeast wind sent this dirty weather swirling over Oahu to dump its moisture on the 2,800-foot-high Koolau range, which overlooked Pearl Harbor.

Not only was there a good chance that his ships could maneuver off Oahu undetected, but, once they launched their planes, the pilots could roar through the rain clouds and burst into clear, sunny weather over Pearl Harbor. The canny Yarnell decided to add one more touch to his plan. He would attack early on Sunday morning.

At nightfall on February 6, 1932, Yarnell’s Blue task force was plowing through heavy seas 60 miles northeast of Oahu. The ships were running with no lights, under absolute radio silence. In the predawn murk on February 7, with the seas still mountainous, Yarnell launched 152 planes from the Saratoga and the Lexington . It was a daring gamble, sending the biplanes of the day aloft from the bucking, rolling carriers. But not a plane was lost.

An hour later, Yarnell’s fliers came out of the clouds shrouding the Koolau Range, and there lay Pearl Harbor below them in the sunshine, getting ready for a peaceful Sunday. Yarnell’s fighters “strafed” lines of planes parked on runways, while his dive-bombers dumped 20 tons of theoretical explosives on air fields, ships in the anchorage, and Army headquarters at Fort Shatter. Not a single fighter rose to oppose them.

The New York Times correspondent covering the Grand Exercises reported that the Blue planes “made the attack unopposed by the defense, which was caught virtually napping, and [they] escaped to the mother ships without the slightest damage being inflicted on them.” He also noted that the Black defenders had yet to locate the Blue fleet 24 hours after the attack.

The Black commanders put up a vigorous defense—after the fact. They persuaded the umpires to rule that 45 of Yarnell’s planes had been hit by antiaircraft fire. They also pointed out that their battleships were at sea when Yarnell attacked and insisted that in a real war they would have soon caught up with his carriers and massacred them with their long-range guns.

A few air-minded admirals, including the outspoken Yarnell, argued that his Blue attackers had won a stunning victory that demanded a re-evaluation of American naval tactics. But the battleship admirals, a comfortable majority, quickly voted them down. In the end, the final report of the Grand Exercises’ umpires made no reference whatsoever to Yarnell’s Sunday-morning raid. On the contrary, the umpires concluded: “It is doubtful if air attacks can be launched against Oahu in the face of strong defensive aviation without subjecting the attacking carriers to the danger of material damage and consequent great losses in the attack air force.”

But though the U.S. Navy refused to pay attention, the navy the admirals worried about in Plan Orange immediately grasped the significance of Harry Yarnell’s raid. Like all major powers, the Japanese paid close attention to a potential enemy’s naval maneuvers, and their observers forwarded a thorough report of Yarnell’s exploit to Tokyo. In 1936 Japan’s Navy War College circulated a monograph, Study of Strategy and Tactics in Operations Against the United States . One of its principal conclusions was: “In case the enemy’s main fleet is berthed at Pearl Harbor, the idea should be to open hostilities by surprise attack from the air.”

The next year, Japan declared war on China. The admiral in command of the U.S. Asiatic Fleet was Harry Yarnell. He was bitter about his assignment to what was known in the Navy of that time as “the small fleet.” The admiral was paying the price for his outspoken advocacy of airpower.

Admiral Yarnell repeatedly urged the United States to take a stronger stand against Japanese aggression. He was ignored as he had been when he spoke out for airpower. Between 1936 and 1940, the Navy laid keels for 12 battleships and only one aircraft carrier. In 1939 Harry Yarnell retired, a baffled, disappointed man.

So, on another Sunday a few weeks short of a decade later, another carrier task force, undetected beneath thick clouds, operating under radio silence, plowed through heavy seas northeast of Hawaii. This time, Admiral Yarnell’s colleagues would get the point.