Why the Pearl Harbor attack succeeded

Good discussion on the unavoidable conceptual limitations of intelligence analysis that made surprise highly likely on 7 December 1941.

Pearl Harbor's Overlooked Answer

Accurately assessing a potential enemy threat hinges on one’s appreciation of the enemy’s capabilities. If you don’t know what your adversary can do, it is nearly impossible to predict likely operational targets or ways to forestall attacks. In the case of the Pearl Harbor attack, the U.S. Navy had no real inkling of Japanese carrier warfare capabilities and therefore could not accurately assess likely operational targets. Not only that, but Japan’s carrier force—known as Kido Butai —was evolving so quickly on the eve of the Pacific war that almost no naval intelligence organ would have been able to track, internalize, and gauge those capabilities. An all-encompassing answer to the reasons for Japan’s surprise is elusive. But examining the extraordinarily rapid development of Japan’s carrier force in late 1941 reveals a stark picture of the U.S. Navy’s odds of being able to understand the type of foe it was going up against.

The most important facet of the Japanese attack—the thing that made it so stunning—was the sheer number of aircraft involved. The Japanese did not just assault Pearl Harbor; they simultaneously hit every major airfield across the breadth of Oahu—Ewa Mooring Mast Field, Naval Air Station Pearl Harbor, Naval Air Station Kaneohe Bay, Wheeler Field, Hickam Field, and others—to remove American airpower as a threat to Kido Butai ’s carriers. Simultaneously hitting so many targets required massive numbers of planes—183 and 171 in the two attack waves. That was unprecedented.

In fact, Kido Butai was a truly revolutionary weapon system for its time because it embodied the conceptual leap from single-carrier to coordinated multicarrier operations. Kido Butai ’s ascendancy would last only about six months before it was permanently mauled at the Battle of Midway, but during that time there was nothing else like it. The U.S. Navy would not acquire a similar sophistication until roughly late 1943—more than two years later. 

As Hayek said: "Without a theory, the facts are silent." And the US Navy did not have the theory that could have lead analysts to "connect the dots" in such away as to predict a carrier strike on Pearl Harbor.

The author covers this ground here is a pretty good lecture for those youngins' who prefer to take three times as long to learn half as much.