The Secret War

by Max Hastings

  From 1942 onwards Ōshima reported the sailings to Japan of blockade-running vessels, and later submarines. The combination of intercepts from his Berlin embassy and Kriegsmarine signals snared by Bletchley and Op-20-G enabled the Allies to wreak havoc with attempts by the Japanese to break the Allied blockade and carry either commodities to Europe or technological prizes homeward. Once surface blockade-runners had been disposed of, and the Axis was reduced to underwater communication, from 1942 onwards fifty-six load-carrying submarines were dispatched, of which twenty-nine were sunk, three abandoned their missions and one was interned. Of twenty-three which completed a one-way passage, only five succeeded in returning home intact, survivors of devastation by sigint.

  Churchill was prompted to launch a pre-emptive British invasion of French Madagascar by a 17 March dispatch from the ambassador asserting that Japan would receive Germany’s full support in attempting to secure the island for itself. On 27 July Tokyo told the baron that all his urgings had been in vain: there would be no Japanese attack on the Soviet Union – on 5 August Franklin Roosevelt forwarded these tidings to Stalin in a personal message. The Soviet warlord may have remained sceptical nonetheless, since only six weeks earlier the US president had given him a contrary warning.

  On 21 September 1942, Ōshima reported the serious depletion of German oil stocks, which could only be remedied by the capture of the Caucasus – then deemed imminent – ‘after which the situation will not be as discouraging as it now looks’. The ambassador urged Ribbentrop that the Wehrmacht should use poison gas to ensure the successful invasion of England, which the Japanese still considered should be a priority objective long after Hitler had abandoned it. On 23 September Ōshima renewed his pleas to Tokyo that Japan should attack Russia: ‘Let us join forces with the Germans and be in on the kill.’

  On 28 November, Japan’s foreign minister wrote to Ōshima dismissing his optimistic forecasts and highlighting German weakness, especially in oil, along with failure to take Stalingrad: ‘You say that Germany has weakened Russia. Well, what about Russia weakening Germany? … I think you would be very wrong if you supposed that it is impossible for the Soviets to come back with a swift blow, and that right soon. I think you had better wait a while before judging Soviet forces to be so weak … However you view it, Germany cannot easily get into the Middle and Near East. Now what we want is for Germany to ready itself for a long war.’ Ōshima passed back explicit assurances from Hitler and Ribbentrop that Germany would make no separate peace with Russia, though in Washington and London doubts persisted that the Nazis might change their minds, as the strategic tide turned against them. In December 1942 Ribbentrop confided Berlin’s serious alarm about the North African situation following the Allied ‘Torch’ landings.

  Slowly but surely, Anglo-American intelligence analysts, who had been initially wary about the authority of Ōshima’s communications, realised how much trust he commanded among the top Nazis. Never in history had belligerents been empowered to eavesdrop on the conversation of their enemies’ policy-makers, as now they were. On 15 December 1942 the ambassador reported Ribbentrop acknowledging that ‘the war with Russia is not progressing as expected’. After spending two hours with Hitler on 21 January 1943, Ōshima quoted him as saying: ‘I don’t want you to think that I am weakening in my conviction that we shall win, but … it is clear that if, in order to destroy the striking power of Russia, you Japanese would, from the East, take a hand and help us out, it would be very advantageous in getting this job off our hands.’ On 2 February the Japanese diplomat reported with startling bluntness that the defeat suffered by the German army at Stalingrad was ‘the greatest disaster to have overtaken it since Napoleon crushed the Prussians at Jena [in 1806]’. At a time when the Soviets were telling Washington and London almost nothing credible about the course of the war, here was authoritative intelligence about the transformation of the Eastern Front.

  Ōshima continued: ‘Since Germany has been fighting Russia, Hitler and the generals have been at odds over the conduct of the war, and now is the time for [him] to stop and think … The military say that it is not that they want to quarrel with Hitler, but that winning the war is the first consideration. [He] understands this and will, in all probability, willingly give in. It is rumoured that a number of the generals who have been in disgrace will soon be brought onto the staff again and that Field-Marshal Keitel will be moved [from his position as chief of the high command]; however, so far there seems no certainty as to these matters.’

  In May 1943 another Japanese general, Kiyotomi Okamoto, was a member of a large delegation that travelled by rail across the Soviet Union, with which his country was not yet at war. The visitors compiled exhaustive notes on everything they saw from their train, counting boxcars, oil tankers, aircraft on airfields, for a fat dossier they proudly presented to Hitler, and which was afterwards read by Tokyo, Arlington Hall and Bletchley. All these audiences may have questioned the value of such nuggets as ‘2nd field (about 4 kilometres north of Alma Ata station). One Douglas passenger plane and about 40 single-seater, slow training planes of uncertain type, a wireless station and three two-storey barracks. One plane taking off, landing and taking off again.’ There were pages of such stuff, characteristic of intelligence flannel of all nationalities.

  In justice to the Japanese, however, their overall estimate of the Soviet Union’s combat power, compiled in Tokyo, was both honest and reasonably sound, given that it was drafted for a partly Nazi readership: ‘The Stalin regime, through able management and careful mobilization, has rallied all resources of the state to combat Germany. The army and people are firmly behind Stalin and war consciousness is running high.’ The foreign minister, now Mamoru Shigemitsu, wrote to Ōshima on the same date – 28 April 1943 – saying that the Tokyo government feared that ‘Germany may lose all her self-reliance and that in the meantime America and England will be left free to strengthen their striking power and finally to launch a great offensive.’ Ōshima was urged to exert his influence and pass on to the Nazis Japan’s strategic assessments, to encourage Germany to pursue a separate peace with the Soviets.

  It was three months before the ambassador had another personal meeting with Hitler, but on 30 July, following the disaster at Kursk, the Japanese did indeed urge peace. Germany’s Führer dismissed this fantasy, saying, ‘Don’t you know that if I did [the Soviets] would beyond any peradventure of doubt reach out, clasp hands with the United States, and squeeze you Japanese to death between them!’ Hitler lamented Italy’s collapse, saying, ‘What an ally! If we had only had you Japanese in the [geographical] position of Italy we would assuredly already have won this struggle.’ Following a further meeting at the Wolf’s Lair on 9 October 1943, Ōshima told Tokyo that Hitler had told him that he was ‘inclined to believe’ the Allies would land in the Balkans instead of moving north in Italy. On Russia, Hitler said, ‘we are making our stand … but, depending on whether or not the Soviet forces resume the offensive, we may fall back to the line which we have prepared on the Dnieper. In the north, if the worst comes to the worst, we can retire to a second defence line which we have prepared across the narrow strip of land adjoining Lake Peipus … I think it the best policy first to strike at the American and British forces as soon as we get the chance, and then to turn on the Soviets.’

  In November 1943 Ōshima wirelessed a sixteen-page report to Tokyo, describing a tour he had just made of the Atlantic Wall, and detailing the locations of sixteen German coastal defence divisions. He emphasised the ability of strongpoints to fight independently, and made plain the German expectation that the Allies would land in the Pas de Calais. An American codebreaker bore witness to the thrill that ran through him as he worked on reading the Japanese dispatch, and understood its momentous significance: ‘Within a few hours the magnitude of what was at hand was apparent … I was too electrified to sleep.’

  Ōshima suggested to Ribbentrop that the British and Americans might make a preliminary descent on
Normandy or Brittany. On 23 January 1944 Hitler told his Japanese friend, ‘beyond any doubt the most effective area [for the main landing] would be the [Pas de Calais]’. The ambassador’s February, April and early May reports on the invasion prospects ignored Normandy, and it was obvious that Ōshima’s confusion of mind reflected that of the entire Axis high command. On 19 May he told Tokyo that an Allied landing might be staged in Dalmatia, Norway or southern France. The following day, he suggested that it could take place in Sweden, ‘however Jodl [operations chief of OKW] told me that he does not think as I do’.

  A second Allied source within the Japanese embassy also deserves mention. It came on stream in March 1944 when Op-20-G, with assistance from Hugh Alexander’s team at Bletchley, broke the ‘Coral’ naval attaché cipher. Vice-Admiral Katsuo Abe, chief of the naval mission to Germany, was a more intelligent and certainly much more sceptical observer than his ambassador – Op-20-G referred to him gratefully as ‘Honest Abe’. He too sent copious reports to Tokyo, especially informative about Dönitz’s new Type XXI and Type XXIII U-boats, both with very high underwater speeds, and fitted with Schnorkel breathing devices. Abe gave detailed technical specifications for the submarines and reported regularly on their production schedules, especially after personal briefings by Dönitz and his constructors in April and August 1944. By that stage of the war, Abe – unlike Ōshima – was in no doubt of the inevitability of German defeat, asserting on 21 August: ‘I regret to say that it is hard to see what the Germans can do that will suffice to bridge the yawning gap between the material and military strength of themselves and their opponents.’ He reported on the serious impact of American bombing on German oil production – a crisis about which Albert Speer also briefed Ōshima on 18 August.

  Allied commanders had by now become as eager as the ambassador himself for his meetings with Nazi leaders, which were as useful as holding such conversations on their own account. George Marshall acknowledged later that the Japanese envoy had become ‘our main basis of information regarding Hitler’s intentions in Europe’. On 27 May Ōshima reported on his latest session with the Führer at the Burghof: ‘Judging from relatively ominous portents, I think that diversionary actions will take place against Norway, Denmark, the southern part of western France, and the coasts of the French Mediterranean – various places. After that, when they have established beachheads on the Norman and Brittany Peninsulas and [have] seen how the prospects appear, they will come forward with the establishment of an all-out Second Front in the area of the Straits of Dover.’

  Eisenhower read this message on 30 May. Here, for the Allied high command, was the most authoritative possible confirmation of German confusion of mind, intensified by Allied deceptions. And the gusher of priceless insights, of precious reassurance, continued to pour forth after D-Day. On 8 June Ōshima reported the Germans saying that the Normandy invasion still left them uncertain whether the Allies ‘will later attempt a landing in the Calais–Dunkirk area’. Next day he added that the Germans ‘are now on their guard against landings in the Calais and Saint Malo directions’. On 6 July he messaged Tokyo: ‘Germany is still waiting for Patton’s [army] group to engage in a second landing operation in the Channel area’; a month after D-Day, the ‘Fortitude’ deception was still working its spell.

  On 20 July, within seven hours of the bomb explosion in Hitler’s headquarters Ōshima was one of the first to confirm the Führer’s survival. On the 23rd, after a long talk with Ribbentrop he told Tokyo: ‘The attempt on Hitler’s life is the most serious occurrence for Germany since the outbreak of the war.’ It was always known that there were anti-Nazis among the old Prussian general staff, he said, but they had remained mute as long as the war was going well. However, ‘more recently, the war situation has deteriorated to the point of producing such an event as that which has just taken place. Judging from the information which has … so far been made available, the group of rebels was not very large … However, in my opinion it will almost inevitably have unpleasant domestic and foreign repercussions … Although Germany has received hard blows both within and without, the fighting spirit of the German leaders is high, and they continue to exert their best efforts to bring the present war to an end with a clear-cut victory.’

  In the spring of 1945 Ōshima sent detailed reports on living conditions in Berlin, because there was nothing more useful to be said about strategy. In March, Ribbentrop informed the baron of the outcome of the Yalta conference, giving details derived from an OKW/Chi decrypt of a message from the Polish government in exile. Ōshima conducted a last phone conversation with the Nazi foreign minister before himself leaving the capital for southern Germany on 14 April, telling Tokyo that ‘it was planned to transfer the high command and government to the south after they have watched developments a little longer’. Though Eisenhower’s headquarters had neglected Ōshima’s warnings before ‘Autumn Mist’ – the December 1944 Ardennes offensive – they readily succumbed to his talk of a Nazi fortress in the south, which skewed Anglo-American strategy in the closing days of the war.

  Ōshima provided the Allies with their most important insider glimpses of attitudes within Hitler’s circle. If his reports were often mistaken – because Nazi leaders told him falsehoods, some of which they believed themselves, especially about their own military prospects – they provided everything that could be asked of any informant: the truth as it seemed at the time to a privileged spectator. He was more useful to Washington and London than would have been any Nazi or Japanese renegade, better placed than the Red Orchestra or ‘Lucy’ Ring. He was the spy who never knew that he spied, the unknowing betrayer.

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  Peter Calvocoressi, one of Bletchley’s codebreakers and later chroniclers, wrote that from late 1942 onwards, if the globe had been combed to identify the people who knew most about – for instance – every operational and organisational aspect of the Luftwaffe, these would have been found not in Germany, but in Britain and America. The same was true of the Abwehr, and indeed of every other branch of the enemy’s armed forces and institutions – though emphatically not of the German economy. Signals intelligence became so central to the Allied war effort that from 1944 onwards the Americans became reluctant to bomb identified Japanese wireless communications centres, because their output seemed more useful to Allied military operations than to those of Nippon. Between 1942 and 1945 the United States spent half a billion dollars a year on sigint, and this has been justly described as its most cost-effective investment of the conflict.

  After Pearl Harbor, Henry Stimson recognised that beyond the tiny team of SIS cryptanalysts who had broken Purple, its wireless intelligence apparatus was weak: only four officers were working on Japanese army traffic, and the Signal Corps leased just thirteen tabulating machines – IBM would never sell them – against four hundred in 1945. On 19 January 1942 Stimson appointed as a special assistant Brooklyn-born lawyer Alfred McCormack, with a brief to examine the whole field of sigint. Thereafter events moved swiftly. The Signals Intelligence Service moved from Washington’s Munitions Building to a former girls’ school, Arlington Hall – ‘the salt mines’ – thereafter the hub of military decrypt activities, which soon occupied several dozen brick and wood-frame buildings in the grounds, and eventually employed 7,000 people, many of them civilians and women. A Section handled diplomatic and clandestine material. B Section studied the Japanese army; its card index eventually identified 46,000 enemy officers. C – ‘Bunker Hill’ – addressed German material forwarded from Bletchley Park. The army also assumed sole responsibility for handling Japanese diplomatic traffic. Despite repeated protests, however, until June 1944 Arlington Hall had no control over interception, which remained the jealously guarded bailiwick of the Signal Corps, whose intercept arm and cryptographic school took over Vint Hill Farms at Warrenton, Virginia. The need to create a network of interception stations almost from scratch was a serious handicap for the army cryptanalysts until the last stage of the war.


  Col. Carter Clarke was appointed to direct a new and highly secret ‘Special Branch’ based at the Pentagon, with McCormack as his assistant, to analyse Ultra material from both Arlington Hall and Bletchley Park. McCormack recognised the army’s dire shortage of trained intelligence officers. Some senior generals, including George Marshall, were slow to correct a weakness they shared with many professional soldiers of all nationalities – they thought too much about what they themselves might do, not enough about the enemy’s capabilities and intentions. Colonel McCormack, as he became, hired and put into uniform hundreds of lawyers, whom he believed had the appropriate training and skills to analyse complex data. He visited Bletchley in April 1943 with Lt. Col. Telford Taylor and William Friedman, and thereafter adopted many British procedures for handling Ultra material and ensuring its security – though never British rates of pay. A woman graduate serving at Bletchley started on £2 a week, while her American counterpart earned five times as much. Special Branch grew to an eventual strength of four hundred, with Taylor heading its most important out-station at GC&CS; this had a direct teleprinter link to the Pentagon, and eventually a cluster of British-built bombes under its own control. Most of the American contingent proved to be exceptionally able people, who made a notable contribution. Stuart Milner-Barry said that their coming was ‘one of the luckiest things that happened to Hut 6’.