TheCodeBreakers
have called Short in Hawaii. The scrambling apparatus stood in a room
next to his office, thus obviating the possibility of tapping the
conversation in unscrambled form, as was done in commercial cases.
But Marshall knew that scramblers afforded protection merely against
casual listeners; they could be penetrated by a determined eavesdropper
with proper equipment. He had on several occasions warned the
President about security on his transatlantic telephone conversations
with Ambassador Bullitt in France and later with Churchill—a wise
move, for, though he did not know it, the Nazis had already penetrated
that scrambler. The Japanese had evidenced some interest in the San
Francisco-Honolulu scrambler, and Marshall was acutely sensitive "that
the Japanese would have grasped at most any straw" to suggest to the
isola-
tionists that the administration had committed an overt act that had
forced the Japanese hand. Japanese interception of a scrambler warning