Should we be surprised that we were surprised at Pearl Harbor?

The “intelligence failure” that wasn’t

Maybe the real failure is in our understanding of how intelligence works and what it can do

Puzzles and mysteries

Risks and Riddles

There’s a reason millions of people try to solve crossword puzzles each day. Amid the well-ordered combat between a puzzler’s mind and the blank boxes waiting to be filled, there is satisfaction along with frustration. Even when you can’t find the right answer, you know it exists. Puzzles can be solved; they have answers.

But a mystery offers no such comfort. It poses a question that has no definitive answer because the answer is contingent; it depends on a future interaction of many factors, known and unknown. A mystery cannot be answered; it can only be framed, by identifying the critical factors and applying some sense of how they have interacted in the past and might interact in the future. A mystery is an attempt to define ambiguities.

Puzzles may be more satisfying, but the world increasingly offers us mysteries. Treating them as puzzles is like trying to solve the unsolvable--an impossible challenge. But approaching them as mysteries may make us more comfortable with the uncertainties of our age.

It is tempting to reduce all intelligence questions to puzzles. It is appealing to think that Benedict Cumberbatch can single-handedly defeat the Nazis by breaking their unbreakable Enigma ciphers.

Unfortunately, life rarely imitates art when the stakes are highest.

If our intelligence systems and all our other channels of information failed to produce an accurate image of Japanese intentions and capabilities, it was not for want of the relevant materials. Never before have we had so complete an intelligence picture of the enemy.
Roberta Wohlstetter, Pearl Harbor: Warning and Decision

In 1941, the commanders at Pearl Harbor thought they were solving a complicated puzzle. In reality, they faced an insoluble mystery. Tragically, as the US got better at solving the known puzzle, we became more vulnerable to strategic surprise at Pearl Harbor.

Without a theory, the facts are silent.
Friedrich Hayek

Every puzzle is grounded in a theoretical framework; that is what makes it challenging yet solvable. Intelligence work looks like a puzzle when analysts and officers can uncover new pieces of information which when fitted into an existing and valid theory provide timely warnings and actionable estimates.

With an invalid theory, facts are not always silent sometimes they become positively misleading. That is why we were surprised on 7 December 1941. Contra Wohlstetter, in the last half of 1941 we no longer had a “complete intelligence picture of the enemy.” We were blind and deaf.

This was not a failure of US intelligence. The Japanese Navy had invalidated our theories with series of sweeping, even revolutionary advances in their capabilities. Yamamoto then harnessed these new capabilities to overturn twenty years of Japanese strategic planning. And it all happened with almost perfect secrecy.

In 1941 our “Theory of Japan” was anchored on a few key premises:

1. In the event of war with Britain or the US, Japan would have to quickly secure access to the resources of the Dutch East Indies. Without these, her war economy would be strangled in a matter of months.

2. Given the distances between Japan’s bases and her targets, Japan would have to depend on her aircraft carriers to provide fighter cover and close air support for the invasions and land campaigns.

When Japan moved to occupy southern Indochina in July 1941 the carriers went south to support the invasion thus confirming this premise.

3. Strategic logic compelled Japan to engage the US Navy in the western Pacific. The long voyage of the Battle Fleet to the Philippine Sea would afford the Japanese submarines and land-based bombers plenty of opportunities to reduce the US strength prior to the decisive battle. Perhaps most importantly, this “home waters strategy” would conserve precious fuel (see point #1).

US analysts knew that Japanese war plans had been based on this logic for two decades.

4. We expected Japan to seize the strategic initiative with surprise attacks. In the Philippines and Malaya, surprise might be decisive. Such an attack on Pearl Harbor would amount to little more than an annoyance: Japan lacked the forces to mount a strategically meaningful attack that far from her bases. One cannot fault the US high command for focusing on the more dangerous and more probable threat.

All of these points were true and valid in January 1941. All of them had been falsified by 1 December 1941.

The puzzle had become a mystery. Worse, this transformation left few traces for the intelligence services to investigate.

The only way that the US could have known this is to have placed a spy on Yamamoto’s staff. That was their only hope of unraveling the mystery.

Paradigm Shift

Pearl Harbor's Overlooked Answer

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.
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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.

No matter how many Japanese messages our code breakers read, we were never going to discover the secret. None of the important and useful information was included in diplomatic cables; Yamamoto’s new strategy was not broadcast to the nation nor was it shared with Japan’s allies.

There was no signal -- only noise.

Actually it was worse than that. Under the old, now outdated theory, the Japanese movement toward Malaya meant that the risk to Pearl Harbor had actually decreased.

All prewar assumptions about Japanese aggression had been based on the belief that Japan lacked the strength to mount more than one invasion attempt at a time.
H. P. Willmott, Empires in the Balance

Finally, underpinning all the risk assessments and intelligence estimates was one bedrock assumption: Japan was a nation-state and nation-states behave rationally. Launching an unprovoked surprise attack on US soil would drag Japan into an unlimited war with a country that had twice her population and 10 times her industrial capacity. In short, a war she was sure to lose.

No rational actor would do such a thing.