Piercing the Fog - Air Force Historical Studies Office

Early Intelligence Organization
when 3 10 Japanese witnesses also denied charges that Japan had rearmed the
mandated islands before the war, although Japan did deepen the harbors and
built airfields and roads there.’33 Amelia Earhart aside, the mandated islands
remained a blind spot in American military and naval intelligence prior to Pearl
Harbor. Intercepted radio traffic, however, alerted the Pacific Fleet to extensive
activities there, and the United States eventually determined that Japan’s Fourth
Fleet and part of the Sixth Fleet’s submarines were based at Truk and Kwaja-
lein
In the summer of 1941, General Arnold found Adm. Harold R. Stark, the
Chief of Naval Operations, very much worried about what the Japanese were
doing at Truk and Rabaul. Arnold arranged for some of the B-17s going to the
Philippines to fly off course and take photographs of the two islands. In the
confusion that attended the Japanese attack on the Philippines in December, the
photographs were lost without having contributed to war preparation^.'^' In late
November the AAF ordered B-24 bombers equipped with photographic
capability and fully armed to be sent over Truk and Rabaul to take pictures from
high altitude. The first such B-24 arrived in theater without guns, and it was not
possible to switch armament from the B-17s already there. Before the proper
weapons could be sent, the Japanese attack on Clark Field had destroyed the
B-24~.‘~~
Explaining the inadequacy of the estimates of likely Japanese actions in late
1941, Miles pointed out that at the time MID had been heavily concerned with
Europe. “We were still primarily concerned, up to November 1941 ,” he said,
“with the European war, the outcome of that war. We were still feverishly
preparing for what we called hemispheric defense. The success of German arms
was the most obvious threat to the Western Hemisphere.” In early December,
General Miles thought that a Japanese line of action against the south was “very
probable” and that southern expansion would involve the Philippines. If the
United States went to war with Japan, Hawaii and Panama might very well be
attacked, but not immediately. Miles knew that the Japanese were capable of
making an attack on Hawaii. “I did not believe, up to a very late date, that it was
probable that they would make that attack at the outbreak of war, for the reason
that . . . such an attack . . . had to result from two separate decisions of the
Japanese: one to take on a war with a great naval power, and presumably with
two great naval powers. . . and second, to start that war, or at least make this
attack on a great fortress and fleet, which inherently jeopardized the Japanese
ships making the attack to some extent, and which rested almost solely for
success on the unpredictable circumstances that they would find that fortress
and that fleet unprepared to meet that
Arnold offered a similar estimate, although with less elaborate explana-
tions: “Looking back on it, I am convinced now that we all assumed that the
Japs would attack the Philippines. We were fairly sure that they would cut our
air line, because they had to cut our line to stop our heavy bombers from getting
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