Piercing the Fog - Air Force Historical Studies Office

Piercing the Fog
Maj. Gen. Hoyt S. Vandenberg Maj. Gen. James H. Doolittle
original German sender put into an Enigma message. If the latter was inaccurate
or incomplete, so too was ULTRA. Sometimes originators were deliberately
inaccurate; more often intercepted messages were incomplete either in their
content or in their assessment of a situation!’
ULTRA was incomplete in the sense that BP, for all its excellence, could not
intercept every German Enigma signal, and many of the signals that it did
intercept were incomplete or could be only partially deciphered. While the
number of signals BP sent to the field rose significantly between 1943 and
1944, what it presented often resembled a jigsaw puzzle with at least some
pieces missing. Sometimes the available pieces were sufficient by themselves
to recreate the total picture. More often, the blanks could be filled in only by
other sources or extrapolated on the basis of what was available. Increasing the
difficulty of this exploitation, particularly with regard to the enemy’s intentions,
was the fact that BP only rarely intercepted communications between senior
enemy headquarters and among senior commanders. Most Enigma signals
contained information that related to activities or orders representing only
portions of an overall operation or reorganization.
The role of the intelligence officers in Hut 3 was crucial, for they
determined the initial value of a given message and prepared the signals to
operational commands. Not every message was forwarded to all headquarters.
The typical message leaving Hut 3 contained the English translation of the
German text (with emendations explaining missing words or sections) for a
field commander’s consideration. Also on the message would be, whenever
possible, notations putting the text into the context of previous intercepts, such
as the state of the known German command organization, supply arrangement,
or the like. Not all of the SSOs assigned to air headquarters agreed about the
sufficiency of what their headquarters received. Some SSOs appear to have
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