by Robert W. McDonald

Created on: March 26, 2009

The question of whether or not Franklin Roosevelt had advance knowledge of the Japanese Navy's plan to attack Pearl Harbor was raised within days of the attack. Since that time, such speculation has been a common theme in a number of books and essays. The purpose of this posting will be to challenge two of the more common misstatements of such literature that are often presented as historical "fact."

The misstatement that is perhaps the most frequently cited states that the American military intelligence community had "broken" the Japanese encryption codes which were in use prior to the attack.

This is partially correct. The Americans (as well as British and Australians) had broken the Japanese diplomatic code (known as PURPLE) but had only partially broken the code in use by the Japanese Navy (known as JN-25). As part of its routine procedure, the Japanese would periodically introduce revisions (new "versions") of JN-25 which severely constrained the code-breaking ability of the American forces in the Pacific. In fact, the Americans were not aware that the Japanese fleets used in the attacks on both Pearl Harbor and the Philippine Islands had left Japan's territorial waters simply because the Americans were unable to decipher the coded radio traffic!

The other common misstatement is to the effect that the US Navy's aircraft carriers had been secretly ordered "out of harm's way."

The three carriers assigned to the Pacific Fleet; Enterprise,
Lexington, and Saratoga were disposed as follows on the morning of December 7th:

Enterprise had left Pearl Harbor on November 27 to deliver aircraft to Wake Island and was positioned some 200 miles west of the island of Oahu; Lexington had set sail on December 5 to deliver aircraft to Midway Island and was positioned 500 miles south of that island, and Saratoga (which had just undergone a major overhaul in Bremerton, Washington) was entering the harbor at the San Diego Naval Air Station when the attack on Pearl Harbor began.

As the historical record has proven, the Roosevelt administration felt that an attack by Japan on the United States would be "insanity" and that the United States could easily defeat Japan even if it did attack. Much of this arrogance on the part of the Americans was based on its racial prejudices against the Japanese, that an army of "skinny, short, nearsighted weaklings" were no match for the American military and that the Japanese were technologically incapable of an attack for from its own territory.

The United States paid a dear price in the Pacific for its arrogance, as it would also pay for its hubris in Vietnam a quarter-century later.

In conclusion, the War in the Pacific was not the result of some vague conspiracy. To insist otherwise is to ignore lessons that today's policy planners, regardless of their country of loyalty, should take to heart.

Learn more about this author, Robert W. McDonald.
Click here to send this author comments or questions.