THE CODEBREAKERS

by DAVID KAHN

  “No,” the President said in effect, “we can’t do that. We are a democracy and a peaceful people.” He raised his voice: “But we have a good record.” He tried unsuccessfully to get Admiral Stark on the telephone, deciding against having him paged at the National Theater for fear of causing undue alarm.

  The President then returned the papers to Schulz and, about half an hour after he had entered the study, Schulz left. He found Kramer seated at one of the long tables in the mail room. Schulz gave him the pouch and soon thereafter went home. Kramer, however, continued to the Wardman Park Hotel, where Secretary Knox had a suite. For about twenty minutes, while Kramer chatted with Mrs. Knox and the acting manager of Knox’s Chicago Daily News, the Secretary read the 13 parts. He agreed with Kramer that, even incomplete, it pointed to a termination of negotiations. He went into another room to make some telephone calls, and when he came out he told Kramer to bring the latest MAGIC to a meeting that had been arranged for 10 a.m. the next morning with Stimson and Hull in the State Department. (Bratton had delivered the 13 parts to the night duty officer at State at 10 p.m., admonishing him to get them to Hull at once.) Knox returned the intercepts to Kramer, who then went to the home of Rear Admiral Theodore S. Wilkinson, director of naval intelligence, where Beardall and Army intelligence chief Miles happened to be dinner guests. All three studied the intercept in a room away from the other guests, Beardall reading from an extra copy that Kramer had. They too seemed to feel that negotiations were coming to an end.

  It was after midnight when Kramer left the Wilkinson house. His wife drove him back to the Navy Department, where he put the MAGIC back in his safe in GZ and checked to see if the 14th part had yet come in. It had not. Finally he went home himself.

  In S.I.S., meanwhile, the new teletype that would expedite the forwarding of intercepts was being set up in the “cage,” the barred room where PURPLE traffic was processed. Monitor Post 2 was requested to send in some intercepts as a test. In San Francisco, Harold W. Martin, the noncom in charge, punched onto the teletype tape the intercepts that the post had picked up since airmailing in the bulk of the day’s material, as well as the earlier ones. Among the later ones was Yoshikawa’s final message, which thus became one of the first to move on the direct wire as a real, nontest item. S.I.S. received it a little after midnight. But PA-K2 was a low-priority system, and the message had originated in a consular office. It was set aside to be worked on later.

  Besides, S.I.S. had more important things to worry about. Like OP-20-G, it was going frantic in a search for the 14th part. Captain Robert E. Schukraft, head of the intercept section, and Frank B. Rowlett, the civilian cryptanalyst in charge of the Japanese diplomatic solutions, checked and rechecked to see whether one of the stations had picked it up and had somehow neglected to forward it. The message preambles had said that it existed, but they could find no trace of it. Neither suspected that the Japanese Foreign Office had deliberately held up transmission of this final conclusive part for security’s sake.

  Neither did the code clerks at the Japanese embassy. They had returned from Terasaki’s party about 9:30, and by midnight had completed deciphering of the 13 parts. While they waited for the final section, they busied themselves by disposing of the remnants of the cipher machine they had destroyed the night before. But they did nothing to fulfill the orders of the pilot message to prepare the dispatch for immediate presentation.

  Finally, fourteen hours after the last part of the previous 13 parts had been transmitted, the Foreign Office released the crucial 14th part that broke off negotiations. At 4 p.m., Tokyo time, it ordered it transmitted via both R.C.A. and Mackay Radio & Telegraph Company to ensure its correct reception. An hour and a half later, it wired to the Central Telegraph Office the coded message ordering the 1 p.m. delivery of the 14-part note. This too was sent via the two companies.

  As usual, the indefatigable ear of Bainbridge Island detected the ethereal pulses of both messages. It picked up the Mackay transmission of the 14th part between 12:05 and 12:10 a.m., December 7, local time, and the even briefer one o’clock message between 1:28 and 1:37 a.m. It teletyped them to GYin a single transmission, the 14th part as serial No. 380 of Station S, the one o’clock as No. 381. Brotherhood, who was GY watch officer, ran them through the PURPLE machine. He evidently had some trouble with the 14th part, for it took an hour to break. But by 4 a.m. he had it in English. The three-letter codegroups were quickly translated into punctuation; the message would need little more than typing. The one o’clock message, however, turned out to be in Japanese. He sent it to S.I.S. for translation, knowing that translators were on duty because S.I.S. was beginning its round-the-clock tours. It was a little past 5 a.m., Washington time.

  In the embassy of Nippon, the code clerks who had waited all through the night for the 14th part were, on Counselor Iguchi’s advice, being sent home. Just as they were climbing wearily into their beds, the naval attach é arrived and found the mailbox stuffed with cablegrams. The duty officer telephoned the clerks at their homes about 8 a.m. and ordered them back to work.

  A few hundred miles north of Oahu, the Japanese task force, bristling with guns, planes, and hate for Americans, bore down on the Pacific Fleet. A few hours earlier, a message had arrived from Tokyo that caused Commander Mitsuo Fuchida, the pilot who was to head the first wave of the air attack, to breathe a sigh of relief. It had been relayed from Yoshikawa, and it reported that no barrage balloons had yet been emplaced to protect the fleet from air attack. The same message also caused Commander Minoru Genda to sigh with relief. It stated that the battleships appeared not to be protected by torpedo nets. Genda had conceived the plan of shallow-water torpedo attack on the anchored American ships.

  A little more than an hour after the hands of Honolulu clocks had snipped off December 6 and opened out into the first hours of December 7, the Pearl Harbor strike force received Tokyo’s relay of Yoshikawa’s final message. The American ships were still in harbor, awaiting the ax stroke with fat complacency. They were apparently not even protected by air search. Was it all a decoy? The strike force’s radio officer, Commander Kanjiro Ono, listened intently to Honolulu’s radio station KGMB for any inkling that the Americans knew of them. He heard only the soft melodies of the islands. On Hiryu, the flight deck officer slipped bits of paper between each plane’s radio transmitter key and its contact point to make sure that radio silence, so carefully preserved for almost two weeks, would not be accidentally broken in the last few hours to destroy the element of surprise.

  As Yoshikawa’s final report was being decoded aboard Akagi, Kramer returned to the Navy Department he had left only seven hours before, and began working again. It was 7:30 on the morning of Sunday, December 7.

  Brotherhood’s decryptment of the 14th part was on his desk when he arrived. It took him about half an hour to ready a smooth version, and at 8 o’clock he delivered the neatly typed copy to McCollum. Other copies went to S.I.S. for its distribution. Kramer then worked on other traffic in his office, interrupting himself only once, at 8:45, to bring a copy of the 14th part to naval intelligence chief Wilkinson on his arrival at the Navy Department. At 9:30 he set out to deliver the full 14 parts to the meeting of the three secretaries. He stopped at the office of the Chief of Naval Operations to make sure that Stark had been given the message, which he had, and then walked and trotted to the White House. He got there at about 9:45 and gave the MAGIC pouch to Beardall, who had assigned himself to duty that morning because he thought the 14th part of the message that he had seen at Wilkinson’s house the night before might be coming in.

  Beardall brought the folder to the President, who was in his bedroom. Roosevelt said good morning to him, read the intercept, and commented that it looked like the Japanese were going to break off negotiations. Then he returned the MAGIC, and Beardall took it back to the Navy Department.

  Kramer, meanwhile, had hurried across the west lawn of the White House to the ugly, ornate State Department building, arrivi
ng at about ten minutes of 10. The Army courier appeared at almost the same moment with the MAGIC for Hull and Stimson. Three State Department officials who saw MAGIC—Hornbeck, Ballantine, and Hamilton—were shown the 14th part by Hull’s aide, John Stone, and the group discussed the situation in general terms until the secretaries arrived a few minutes later. Kramer gave his pouch to Knox and headed back to the Navy Department.

  Meanwhile, the translation of the one o’clock message had come up from S.I.S. It was placed in Bratton’s hands about 9 a.m. while he was reading the 14th part. It “immediately stunned me into frenzied activity because of its implications, and from that time on I was busily engaged trying to locate various officers of the general staff and conferring with them on the exclusive subject of this message and its meaning,” he said later. He tried first to get in touch with Marshall, calling him at his quarters at Fort Myer, and was told by an orderly that the chief of staff had gone on his customary Sunday morning horseback ride. Bratton directed the orderly:

  “Please go out at once, get assistance if necessary, and find General Marshall, ask him to—tell him who I am and tell him to go to the nearest telephone, that it is vitally important that I communicate with him at the earliest practicable moment.” The orderly said he would. Bratton called Miles, told him of the message, and urged him to come down to the office at once. Between 10 and 10:30, Marshall called Bratton back. The colonel offered to drive out at once with the one o’clock message, but Marshall told him not to bother, that he was coming down to his office at once. Bratton obeyed.

  Kramer arrived back in GZ at about 10:20, and found there the one o’clock message. It struck him as forcibly as it had Bratton. He at once had Yeoman Bryant prepare a new set of folders for immediate delivery of the intercept. Included in the new set were other messages which S.I.S. had decrypted, and on which Kramer had been working earlier in the morning: Tokyo serial No. 904, which directed the ambassadors not to use an ordinary clerk in preparing the 14-part ultimatum for presentation to the Secretary of State, so as to preserve maximum security; serial No. 909, thanking the two ambassadors for all their efforts; and serial No. 910, ordering destruction of the remaining cipher machine and all machine codes.

  Kramer was about to dart out again when Pering, the GY watch officer, brought in a message in plain-language Japanese, ending with the telltale STOP that indicated it was an INGO DENPO message: KOYANAGI RIJIYORI SEIRINOTUGOO ARUNITUKI HATTORI MINAMI KINEBUNKO SETURITU KIKINO KYOKAINGAKU SIKYUU DENPOO ARITASI STOP TOGO. Kramer Recognized KOYANAGI as the codeword for England, and HATTORI as a codeword whose meaning he did not recall. He consulted his code list and saw that it meant Relations between Japan and (name of country) are not in accordance with expectation. But in his haste he overlooked that the common Japanese word minami, which means “south,” had an INGO DENPO meaning of U.S.A. He interpreted the message as “Please have director Koyagani send a wire stating the sum which has been decided to be spent on the South Hattori Memorial Library in order that this business may be wound up.” Consequently, he dictated a decode that omitted United States: Relations between Japan and England are not in accordance with expectation. Yeoman Bryant inserted this and three other minor messages that had come over from the Army into the folders. Kramer meanwhile made a navigator’s time circle that indicated that one o’clock in Washington was dawn in Hawaii and the very early hours of the morning in the Far East around Singapore and the Philippines, which everybody seemed to be watching. He shoved the folders into the briefcase and dashed out the door.

  He went first to Stark’s office, where the officers were discussing the 14th part, summoned McCollum, gave him the pouch that included the final code-destruction and one o’clock messages, and mentioned to him the significance of the latter’s timing. McCollum grasped it at once and disappeared into Stark’s office. Kramer wheeled and hurried down the passageway. He emerged from the Navy Department building and turned right on Constitution Avenue, heading for the meeting in the State Department eight or ten blocks away. The urgency of the situation washed over him again, and he began to move on the double.

  He half trotted, half walked to State, getting there at about 10:45. Hull, Knox, and Stimson were still meeting. Kramer saw them grouped around the conference table when the door to Hull’s office was opened briefly. He gave the MAGIC messages to Stone, explaining to him how the one o’clock time of delivery of the ultimatum tied in with the movement of a big Japanese convoy down the coast of Indochina, and mentioning in passing that the time in Hawaii would be 7:30 a.m. The final code-destruction message was self-explanatory. Kramer carried a MAGIC pouch to the White House, and then returned, perspiring, to the Navy Department, to busy himself with still more MAGIC. At about 12:30, he spotted the omission of United States from the INGO DENPO message. Because the one o’clock meeting was so close, he telephoned the recipients with the correction, a practice he had followed several times in the past, but reached only McCollum and Bratton. He told them that United States was to be inserted in file number 7148. The force of it had been considerably lessened by the one o’clock message, but Kramer, conscientious beyond the basic requirements of duty, nevertheless planned to send around a corrected version.

  Safford later estimated that OP-20-G handled three times as much material that weekend as on a normal one; the GY log shows at least 28 messages in PURPLE alone handled that Sunday. And these messages were processed much more expeditiously than at any other time in the past, Kramer said. The cryptanalysts had done their duty, and had done it superbly. Events now passed out of their hands.

  In Tokyo, the President’s message to the Emperor had finally been delivered to Grew after a delay often hours. The chief of the censorship office had ordered that all foreign cables be held up for five hours one day and ten hours the next. The order had been issued at the request of a lieutenant colonel on the general staff, who asked that this be done “as a precaution.” The President’s “triple priority” message arrived on one of the ten-hour days, was stalled for the required time, and was finally delivered at 10:30 p.m., Tokyo time.

  Grew immediately arranged for a meeting with Togo and, when the message had been decoded, drove to Togo’s official residence at 12:15 a.m. He requested—as is the right of all ambassadors—an audience with the head of state to present the message, then read it aloud to Togo and gave him a copy. Togo promised to present the matter to the Throne and, despite the lateness of the hour, telephoned the Lord Keeper of the Privy Seal for an audience. Ministers of state would be received at any hour, and the audience was arranged for 3 a.m. Togo began having the message translated.

  It was then about 5:30 a.m., December 7, in Hawaii. The Japanese task force was only 250 miles north of Pearl Harbor. More than 2,000 Americans with less than three hours to live slept or played in blissful ignorance of that fact. The hands of clocks in the Foreign Office in Tokyo, in the code room at the Japanese embassy in Washington, in the War and Navy departments, in Pearl Harbor, circled around and around, but not so quickly as the spinning propellers of Nagumo’s ships. At 5:30, two cruisers catapulted off a pair of scout planes to make sure the Americans were still there.

  The clerks at the embassy had straggled back to work between 9:30 and 10. They began decoding the longer cables first, as experience had shown that these were usually the more important. At the same time, the embassy’s first secretary, Katzuso Okumura, was typing up the first 13 parts of the ultimatum. He had been chosen because the Foreign Office had forbidden the use of an ordinary typist in the interests of secrecy and he was the only senior official who could operate a typewriter at all decently. At about 11:30, code clerk Juichi Yoshida adjusted the Alphabetical Typewriter to the proper keys and typed out a short code message. To the consternation of the entire staff, it turned out to be an instruction to deliver the 14-part message to Secretary Hull at 1 p.m., Washington time. The 14th part had not even been decoded from the sheaf of incoming cables! And only one code machine was left to decipher
all the messages!

  A few blocks away, General Marshall had just arrived at the War Department. On his desk was the MAGIC folder with the 14-part message on top and the one o’clock message under it. He began to read the ultimatum carefully, some parts several times. Bratton and Brigadier General Leonard T. Gerow, the war plans chief, tried to get him to look at the one o’clock message, but it is rather difficult for subordinates to interrupt a four-star general, and he finished the ultimatum before finding the time-of-delivery message. It struck him with the same sense of urgency that it had the others, and he picked up the telephone to call Stark to see if he wanted to join him in sending a warning message to American forces in the Pacific.

  At approximately the same time, Ambassador Nomura was calling Hull to request an appointment at 1 p.m. And 230 miles north of Hawaii, the first wave of Japanese planes was thundering off the flight decks of the carriers.

  Stark was at that moment discussing the significance of the one o’clock message with Captain R. E. Schuirman, Navy’s liaison with State. He told Marshall that he felt that enough warnings had been sent and that more would just confuse the commanders. Marshall thereupon wrote out the dispatch he wanted sent:

  Japanese are presenting at one p.m. Eastern Standard Time today what amounts to an ultimatum also they are under orders to destroy their code machine immediately STOP Just what significance the hour set may have we do not know but be on alert accordingly Stop

  On his desk Marshall had a scrambler telephone with which he could 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 with the Mori message. 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 isolationists that the administration had committed an overt act that had forced the Japanese hand. Japanese interception of a scrambler warning might thus have sent the country to war divided. So Marshall shunned the scrambler telephone and relied on the slightly slower but much more secure method of enciphering a written message.