|The attack on the military
forces of the U.S. at Pearl Harbor Hawaii did not just happen nor was it
a quick reaction to initiatives instituted by President Roosevelt. The
Japanese believed that they were being pushed into a corner by Roosevelt
and felt that they must act to protect the Empire. Gordon Prange in 'At
Dawn We Slept' describes pre-attack events in detail. The description of
these events note the mistakes made on each side.
Japanese Army invaded North China from Manchuria, eight years of combat
with the Chinese began.
gunboat USS Panay, while on routine duty in Chinese waters, was attacked
by Japanese aircraft. We do not know if the attack was intentional or an
accident but Roosevelt looked for ways to punish Japan . Nothing became
of this incident because the Japanese government apologized, paid for
all damages, and promised to protect American nationals.
the continued German military rearmament program and European leadership
capitulation at the Munich conference, President Roosevelt asked
Congress for $500 Million to increase America's defence forces. This
action was done because he believed that Germany was a threat to the
U.S. The Japanese saw this build up as a direct threat to their Empire
because, the U.S. was the only country in the Pacific which could impede
continues its conquest of China by occupying Hainan Island of the
Southern coast. This occupation improved Japans ability to interdict
maritime trade routes.
Because the U.S. was the primary
military threat in the Pacific, Japan had prepared war plans to deal
with this problem, the U.S. had similar war plans aimed at Japan. The
Japanese plan was to conduct one large naval battle against the American
Navy, destroying it, resulting in the inability of the U.S. to interfere
with Japanese expansion through out Asia. Admiral Isoroku Yamamoto
assumed command of the Japan's Combined Fleet in August of 1939. Having
lived in America for several years he knew Americans, the type of people
we were, he knew that this war plan was impractical. He needed a new
plan which would remove the threat of U.S. intervention from his flank.
time between January and March 1940 Yamamoto devised his plan to destroy
the U.S. Navy in Hawaii and demoralize the American people. Prange asks
the question 'Why did Yamamoto think that this attack would crush
American morale since he knew them?' but he does not answer his own
question. No actions were implemented to put the plan in action.
sanctions followed by a trade embargo were imposed resulting in
increased ill-will and additional political problems with Japan. These
trade actions were imposed because Roosevelt was attempting to stop
Yamamoto begins communicating with other Japanese officers, asking them
if an attack on Pearl Harbor would be possible. The final outcome of
these discussions was the attack was possible but would be difficult.
Secrecy and surprise were the two
elements which were most important to the success of this plan. With
that said one wonders how secure was the flow of information around the
Imperial Naval Staff, because on January 27, 1941 Joseph C. Grew, the
U.S. Ambassador to Japan, wired Washington that he had learned
information that Japan, in the event of trouble with the U.S., was
planning a surprise attack on Pearl Harbor.
No one in Washington believed the
information, if someone had believed this information, the Pearl Harbor
attack possibly could have been avoided. While many thought that war
was possible, no one believed that the Japanese could surprise us.
Most senior American military experts
believed that the Japanese would attack Manila in the Philippine
Islands. Manila's location threatened the sea lanes of communications as
the Japanese military forces moved south. Another thought to location of
attack was toward the north into Russia because of the war in Europe
between Germany and the Soviet Union.
the Japanese were conducting preliminary planning for the attack,
Americans were preparing to defend American property. Admiral Husband E.
Kimmel, Commander in Chief of the U.S. Fleet, and Lieutenant General
Walter C. Short, Commanding General of the Hawaiian Department prepared
Hawaii for attack. Defence of the islands was an Army responsibility
though the Navy did play a major role in preparing to repel an attack.
Adm. Kimmel planed on taking his fleet
out of the harbor and confronting the enemy at sea.
With this in mind both officers
communicated with their seniors in Washington attempting to obtain
additional men and equipment to insure a proper defence of all military
instillations on Oahu. At this time, war production of the U.S. was
still limited resulting with the dispersal of material around the world
trying to fill everyone's needs; Britain, Russia, the Philippines and
Kita, Honolulu's new Consul General arrives on Oahu with Takeo
Yoshikawa, a trained spy. As the military of both countries prepared for
possible war, the planners needed information about the opponent.
The U.S. knew that Hawaii was full of
Japanese intelligence officers but because of our constitutional rights
very little could be done. Untrained agents like Kohichi Seki, the
Honolulu consulate's treasurer, traveled around the island noting all
types of information about the movement of the fleet. When the attack
occurred the Japanese had a very clear picture of Pearl Harbor and where
individual ships were moored.
the time period U.S. intelligence officers continued to monitor Japanese
American scientists had developed a
machine, code named 'Magic" which gave U.S. intelligence officers
the ability to read Japanese secret message traffic. 'Magic' provided
all types of high quality information but because of preconceived ideas
in Washington some data was not followed up on and important pieces of
the pre-attack puzzle were missed.
Japanese consular traffic was also
intercepted which provided additional intelligence. While the U.S. had
all the data needed to arrive at a clear picture of Japanese intentions,
the Navy had an internal struggle between the Office of Naval
Intelligence and the War Plans Division about which department should be
the primary collection office. When the War Plans Division was finally
designated the first in line for data, all of the Navy's intelligence
collection was degraded .
To further complicate this problem the
Army had its own Intel office, G-2. At times the Army and the Navy did
not talk to each other, again reducing the ability to divine Japan's
intentions. Finally, Washington did not communicate all the available
information that was received to all commands, at times thinking that
such a transmission would result in duplication. All in all the U.S.
knew that Japan was going to expand its war but the question remained,
where? If U.S. Intelligence people had communicated , preparations for
the attack could have been improved,
Nomura informed his superiors that he had learned Americans were reading
his message traffic. No one in Tokyo believed that their code could have
been broken. The code was not changed.
If the Japanese had changed their
code, the surprise of the attack would have occurred as it did but would
we have been as poorly prepared or could the result been worse? This
mistake would have impacted follow on actions through 1942.
out the summer Yamamoto trained his forces. His staff and the Naval
General Staff finalized the planning of the attack: what route to travel
on, how much fuel would be required for the trip, what U.S. ships would
be in the harbor and where they would be moored.
The Japanese planners also had to
coordinate their own requirement of additional military action around
Indochina. Which action was more important and which would provide the
greatest gain had to be worked out.
sends Saburo Kurusu, an experienced diplomat to Washington as a special
envoy to assist Ambassador Admiral Kichisaburo Nomura, who continued to
seek a diplomatic solution.
Japan wanted the U.S. to agree to its
southern expansion diplomatically but if they were unsuccessful, they
would go to war.
On the 16th the first units,
submarines, involved in the attack departed Japan.
On the 26th the main body, aircraft
carriers and escorts, began the transit to Hawaii.