A few news sources are running a breathless marketing flyer-cum-news article that purports to reveal how newly-revealed intelligence reports From WWII reveal the overlooked signs of the Japanese attack on Pearl Harbor:
Three days before the Dec. 7, 1941 Japanese attack on Pearl Harbor, President Roosevelt was warned in a memo from naval intelligence that Tokyo's military and spy network was focused on Hawaii, a new and eerie reminder of FDR's failure to act on a basket load of tips that war was near.
In the newly revealed 20-page memo from FDR's declassified FBI file, the Office of Naval Intelligence on December 4 warned, "In anticipation of open conflict with this country, Japan is vigorously utilizing every available agency to secure military, naval and commercial information, paying particular attention to the West Coast, the Panama Canal and the Territory of Hawaii."
Warren Meyer at Coyote Blog posted on the subject today, putting the claim in its necessary context. Which is a charitable way of saying that he debunked it without needing to put up a single specific case. In fact, the claim debunks itself.
The Japanese, the (20-page) memo said, were seeking "military, naval and commercial information, paying particular attention to the West Coast, the Panama Canal and the Territory of Hawaii." Put another way, the Japanese were seeking every shred of intelligence relevant to American commercial strength and military readiness in the Pacific. Boy, that narrowed it down! On that basis alone, Roosevelt was supposed to infer an aerial attack on Pearl Harbor and then... do something.
Meyer makes a broader point about the fun of second guessing history, with a cautionary point about ensuring that the context is filled in, and the closes with this:
Historians are failing in their job when they strip these decisions of context (if you really, really want to get on someone about preparedness, how about McArthur, who allowed most of his air force to be shot up on the ground despite having prior notification of the Pearl Harbor attack hours before).
Step into my office, friends. I happen to be the historian for the very Air Force unit whose bombers were destroyed on the ground in the Philippines through the fecklessness of MacArthur's staff. This unit is my
profession.
The bomber boys on Luzon knew they were the tripwire for the war. They considered themselves to be in a state of war a solid week before Pearl Harbor. That's why they were sent to the Philippines in the first place--to be America's Big Stick, with which to dissuade (or failing that, punish) Japanese aggression. Of course Roosevelt knew war was coming. Everyone knew war was coming. Golly gee, there were already two colossal wars going on!
So why did it go so monstrously bad for America in the first 24 hours? Two points to consider:
First, the American military was completely green. Few of the generals had been more than lieutenants and captains in WWI. Nobody with less than 23 years service had any combat experience at all. The theater commanders in the Philippines failed massively and repeatedly; e.g., when they got the bomber force destroyed, or when they retreated to Bataan without taking any supplies. You can compute for yourself the ramifications of their inexperience.
Second, warfare had completely changed in those intervening 23 years. World War II did not resemble its predecessor. America entered World War II with a set of doctrines and tactics that were purely theoretical, and that had to be quickly unlearned. (This is painfully apparent in the history of my unit, which spent months suicidally trying to sink enemy ships with small-formation, high-altitude bombardments.)
In both doctrine and leadership, America and Americans adapted quickly and made up for lost time. Within months, new commanders employed veteran troops with new tactics to much greater effect.
Averting the unpreparedness that doomed us at Pearl Harbor and on the Philippines would have required investments of money and will that Depression-era America did not make. To have been prepared for 1941, America would need to have been more militaristic than it was, without being so militaristic as to alter Japanese designs on the Pacific. I'm not sure that mark even existed.
One thing that definitely would not have helped was a memo asserting that the Empire of Japan was interested in the strategic situation in the Pacific Ocean.
