The Codebreakers: The True Story of the Secret Intelligence Team That Changed the Course of the First World War

by James Wyllie

  On Friday 23 February, the patrician and sanguine Foreign Secretary Arthur Balfour was in a state of excitement as he received Ambassador Page at the Foreign Office. He would later say that the moment when he handed over the document that would change the face of the war was ‘the most dramatic of my life’.

  Page stayed up until 3 a.m. drafting a careful cover letter to Woodrow Wilson to send with the decrypted telegram, which he transmitted later that day. In his letter, the masterwork of Hall is again evident, for though Room 40 had been in possession of the telegram for more than a month, Hall had clearly told Page otherwise, resulting in the ambassador informing his president that the British had ‘lost no time in communicating it to me to transmit to you … in view of the threatened invasion of our territory’.

  Though Zimmermann’s telegram threatened a Mexican invasion of the US only if the US joined the Allied cause, the point was moot when Secretary of State Robert Lansing added insult to injury by revealing to Woodrow Wilson that the Germans had sent their message of war via the American cable that the US had so generously allowed them to use in the name of peacemaking. ‘The President two or three times exclaimed “Good Lord!” … and showed much resentment at the German government for having imposed upon our kindness in this way and for having made us the innocent agents to advance a conspiracy against this country.’

  Despite his naiveté about the dark arts of intelligence, Wilson also wondered if the document might be a fake. State Department counsel Frank Polk had already thought of that, and managed to arm-twist Western Union to release the copy of von Bernstorff’s transmission to the German mission in Mexico City.

  On 1 March, newspapers in the United States and around the world trumpeted the treachery: ‘GERMANY SEEKS ALLIANCE AGAINST US; ASKS JAPAN AND MEXICO TO JOIN HER; FULL TEXT OF HER PROPOSAL MADE PUBLIC; WASHINGTON EXPOSES PLOT’ shouted the New York Times’ front page. The White House had leaked the Zimmermann telegram to the Associated Press, and while the New York Times felt compelled to say – again with abounding irony – that it hadn’t authenticated the contents, it had no hesitation in revealing the depth of Germany perfidy. It seemed to outraged Americans that it was their own government who had broken open the ugly truth of the German betrayal, which was exactly how Blinker Hall wanted it to appear.

  German-Americans immediately saw the whole affair as a provocative fiction. The New Yorker Staats-Zeitung editorialised: ‘The passions of the American public that still doesn’t want to hear of war must be aroused so that it may attain that condition forced by similar means on the people of Italy, Great Britain, and Rumania.’

  The Fatherland’s proprietor and inveterate anti-Allied provocateur George Sylvester Viereck was more bluntly incredulous, calling the telegram ‘obviously faked’ for the simple reason that ‘it is impossible to believe that the German Foreign Secretary would place his name under such a preposterous document’.

  On 3 March, Zimmermann put any doubt to rest, astonishingly confessing to plotting the creation of a Japanese—Mexican invasion of the USA. ‘When I thought of this alliance with Mexico and Japan I allowed myself to be guided by the consideration that our brave troops already have to fight against a superior force of enemies, and my duty is, as far as possible, to keep further enemies away from them,’ he declared in a speech. ‘That Mexico and Japan suited that purpose even Herr Haase [Hugo Haase, a German socialist politician and pacifist] will not deny. Thus, I considered it a patriotic duty to release those instructions, and I hold to the standpoint that I acted rightly.’

  Even with Zimmermann’s admission, the United States – well aware that it was on the march to war – wanted to silence the doubters that still remained. So in one of the most baroque – and, were it not for the outcome, comic – reversals in the history of codebreaking, the US State Department cabled Ambassador Page to ask if the British would permit someone from the US embassy ‘to personally decode the original message which we secured from the [Western Union] telegraph office in Washington … and make it possible for the department to state that it had secured the Zimmermann note from our own people’.

  Blinker Hall was only too happy to go along with the ruse: there was no one in the US embassy who had the slightest idea how to decode the Zimmermann telegram. But in the spirit of the elaborate theatre needed to convince the American people that this was not a slick foreign plot, Eddie Bell came to the Admiralty and looked on as Nigel de Grey decrypted the telegram for him, having no choice but to believe that the jumble of numbers on the telegram meant what de Grey said they did. Ambassador Walter Page accepted at face value Blinker Hall’s claim that it would be pointless to burden the US with the German code book because it ‘would be of no use to us as it was never used straight but with a great number of variations which are known to one or two experts here. They cannot be spared.’

  With this last bit of theatrics, Hall had primed the US for war without giving up the fact that the British were reading secret American communications. Walter Page, who wanted to live another 20 years to be present for the unveiling of Hall’s secrets, wrote in a letter to President Wilson: ‘the man is genius – a clear case of genius’.

  By the middle of March, alarmist reports were coming out of Mexico that the country was swarming with German troops, which it was not, though German spies had found their way south to avoid being on American soil when war was inevitably declared. On the 18th, three American merchant ships, City of Memphis, Illinois and Vigilancia, were sunk by U-boats, with 38 men missing. The New York Times also reported that Germany had announced it had sunk nearly 800,000 tons of Allied shipping since it resumed unrestricted warfare in February – a total of 292 hostile ships and 770 neutrals.

  In early April the galvanised United States Congress authorised Woodrow Wilson to go to war. In a 36-minute speech, Wilson laid out what the country had now accepted: a state of war existed between the United States and Germany. ‘The world,’ he famously said, ‘must be made safe for democracy,’ but in the end, what propelled the United States, finally, into the First World War was the brilliant decryption and dissemination of a document that threatened its own territory, and its own democracy. The United States was fighting a war in Europe so that it wouldn’t have to fight one in Mexico. Pershing would take what he had learned from his Punitive Expedition, especially in the field of intelligence and codebreaking, and use it in the war in France. With a particularly American twist.

  PART III

  Chapter 15

  MASON, MULES AND ROUNDABOUTS

  You would have thought that the disastrous fallout from the Zimmermann telegram would have deterred the Germans from meddling in Mexico: on the contrary, now that America was officially their enemy, there was even more reason to use it as a base for action against the USA.

  Initially, the Germans continued to try and nudge Mexico into open conflict, offering weapons, logistical support, money and debt relief. Kurt Jahnke, who had been instrumental in the bombings carried out on American soil – most notably Black Tom – crossed the border to take charge of subversion and sabotage with ‘an available credit of 100,000 Marks per month’. Instructions relayed to him by telegram from Berlin that passed via Madrid were intercepted and decoded by Room 40. Of particular interest were plans to use German submarines to target trade routes: ‘undertakings against the Panama Canal are highly desirable. If a good opportunity presents itself, the corn ships sailing from Australia to America should be attacked.’

  To facilitate such endeavours, Jahnke was ordered to find places that could serve as secret refuelling sites for U-boats. On 9 June 1917 Room 40 picked up a message sent to the German legation in Mexico City requesting Jahnke ‘to prepare as rapidly as possible a point … for submarines on the Mexican coast’.

  Though there was some considerable panic in America at the prospect of U-boats raiding the West Coast, the threat never materialised. Then, during August 1917, the emphasis of German policy changed: while Mexico would still offer refuge
to agents fleeing American justice, such as Anton Dilger, the biochemical weapons expert, economic penetration became the priority. The aim was to deprive the Allies of resources such as lead, copper and oil by either acquiring control of companies through share purchasing or setting up rival corporations.

  Though large sums were made available, these measures had little impact. A plan to burn the major oil fields at Tampico, which had been abandoned during the Zimmermann scandal, was resuscitated. A German agent was given the job and told that ‘if arson not possible, at least disrupt loading and capacity to supply’. However, von Eckardt, the German resident minister in Mexico City, worried that his hosts were beginning to lose patience with German subterfuge, blocked the operation.

  A project that did go ahead was the construction of a wireless station with a receiver/transmitter capable of sending messages directly to Europe. Hall’s agents in Spain discovered that the Germans had purchased a quantity of high-powered audion valves, which were able to receive long-distance signals and amplify wireless communications, and had shipped them to Mexico. Equipped with the valves, the wireless station, located at Ixtapalapa, just outside Mexico City, was soon up and running and relaying signals to Madrid that were then rebroadcast to the main German station at Nauen. These developments deeply concerned Hall, who feared that such a powerful station would allow the Germans to coordinate their subterfuge in both North and South America without resorting to the telegraph, and thereby cut Room 40 out of the equation.

  Hall decided to send his favourite field agent, the author and adventurer A. E. W. Mason, who had distinguished himself in Spain with his resourcefulness, bravado and cunning, to Mexico City: his priority, to sabotage the wireless station. Armed with a courier’s passport that allowed him to travel ‘freely without … hindrance’, Mason left Liverpool on 19 October 1917, passed through Washington where the passport was countersigned by the British ambassador, and arrived in Mexico City in November.

  Posing as a lepidopterist (butterfly collector), and carrying suitable nets and equipment to maintain his cover, Mason soon found the Ixtapalapa site. After making discreet enquiries, he discovered that German wireless officers from ships interned at Veracruz were coming ashore every night at 11 p.m. to man the wireless station until the following morning.

  Having returned briefly to London to get the green light from Hall, which he duly received, Mason arrived back in Mexico and set about buying up all 11 audion lamps still in circulation there, before turning his attention to Ixtapalapa. His first move was to establish how many lamps were at the station. To assist him he recruited two high-ranking police officers and a burglar, ‘three Mexicans of worth’, and befriended a local dignitary who agreed to join the conspiracy. According to Mason, whose operational notebooks provide the main evidence of his clandestine work in Mexico, this gentleman of ‘high position’ invited the captain of the 40 soldiers who guarded the facility to dinner; also in attendance were two of Mason’s team. A convivial, boozy evening ended in an invitation to visit the wireless station.

  The next morning Mason’s team reported back: ‘the soldiers were in a large room on the ground floor. The receiving apparatus was upon the first floor, and there were 13 audion lamps in use’, plus three spares. They also revealed that there was a window at the end of the large receiving room that afforded an easy drop into a garden enclosed by a fairly high wall. This, however, ‘would present no particular difficulty to the expert amongst the party’, i.e., the burglar!

  After Mason had his agents make another visit to the station, where they were allowed to take photographs, he became convinced his scheme was feasible. The captain of the guards was to be invited to another dinner. Mason’s men would strike in his absence, before the German wireless operators arrived for their shift.

  Mason’s helpers arrived at the station bearing gifts: several jars of pulque, the Mexican equivalent of beer. Having got some of the soldiers thoroughly drunk, a fight was instigated over an alleged insult, which escalated into a general brawl ‘with sticks and fisticuffs’. Taking advantage of the confusion, Mason’s men ‘darted up the stairs into the receiving room, twisted off four of the audion lamps, smashed the rest, jumped out of the window, climbed the wall at the appropriate spot, and dropped into the motor-car which was waiting in the road just beneath. The car was then driven back to Mexico City as rapidly as the abominable roads would allow.’

  This left one audion lamp unaccounted for. Determined to complete the job, Mason got himself invited to yet another party at the station. During the spirited revelries, he pretended to get drunk. Feigning sickness, he slipped out, tracked down the lamp and hid it in his jacket, then made his getaway in a chauffeur-driven car.

  For the rest of 1918, Mason produced a newspaper, El Progreso, filled with disinformation and Allied propaganda, and focused on the movement of suspected German agents back and forth across the border; he ran down one of the Black Tom bombers, and had him arrested in the States, where he was court-martialled. What else he got up to while he was in Mexico is impossible to say for sure. He did not recycle any of his escapades in his novels, as he did with his Spanish adventures. However, two anecdotes he told friends after the war have survived, thanks to Mason’s biographer.

  The first is particularly chilling. Mason claimed to have arranged the assassination of German agents who were trying to set up a portable wireless transmitter in a remote part of Mexico. Mason, who remarked that ‘you can get a man killed out there for five shillings’, put word out on the street that they were carrying diamonds, with the result that ‘no more was heard of them or their wireless’.

  The other anecdote concerned an attempt on his life: ‘Mason received a message that confidential information of utmost value would be divulged if he would go to a rendezvous at a certain address. He agreed, but ever suspicious of Teutonic guile, he thought it advisable to reconnoitre on his own account; and so, his identity suitably disguised, he visited the place – to find it situated on a remote and ill-favoured by-way with a nail-studded door and barred lattices.

  Suspecting that he was being lured into a trap, Mason arrived at the location shortly before the appointed time and hid at a window on the opposite side of the street. Watching from his vantage point, he saw ‘a couple of tough-looking individuals’ go into the building ‘ten minutes before … the hour at which he himself was expected’. Reflecting on this close brush with death, Mason remarked that ‘if I had gone in … I should never have reappeared’.

  Though Mason did not mention these incidents in his official reports, they have the ring of truth about them. Certainly he was involved in a murky and murderous business. The brutal and vicious civil war that was tearing Mexico apart at the time made it an extremely treacherous place to be. Yet it is just as likely that he invented them to entertain and impress his friends. In the world of espionage, fact and fiction often go hand in hand. What cannot be denied is that Mason was one of the most effective agents Hall ever employed.

  By exposing the Zimmermann telegram in the way that he did, with a cover story provided by the Americans, Hall overcame one of his greatest fears: that the existence of Room 40 would become public knowledge. It also showed him that he could use Room 40 intelligence more overtly without raising suspicions about its true origin. As long as the Americans agreed to play ball, further damage could be done to Germany’s international credibility and its capacity to wage war. The question was where to strike next.

  The Swedish Roundabout, which allowed Berlin to communicate with its embassies by using Sweden’s diplomatic channels of communication, was an obvious target. By revealing it to the world, Hall would provide another example of German perfidy and hopefully shame the Swedes into abandoning their pro-German government at the forthcoming elections, replacing it with the pro-Allied alternative. Simultaneously, it would undermine Sweden’s role in helping Germany evade the naval blockade: large quantities of contraband goods were being exported to Sweden and then re-exported
to Germany.

  These gains, however, had to be weighed against the fact that exposing the Swedish Roundabout would deprive Room 40 of the valuable information gained from it.

  Hall, therefore, sought to maximise the impact of further disclosures, and his thoughts turned towards Argentina, a key source of foodstuffs essential to both the Allies and the Germans. From Argentina came wheat, grain and beef, the demand for which spiralled as the war progressed. In 1913, 6.7 million tonnes of shipping operated out of Buenos Aires; by 1917, that figure had leapt to over 20 million.

  Argentine wheat was vital to the Allies’ survival. At the beginning of 1917, they attempted to secure its supply: shortages in Britain were becoming acute, rationing was on the way. Any interruption to this trade would be fatal. Desperate, they agreed to loan the Argentine government 200 million pesos in exchange for 2.5 million tonnes of cereal. A similar situation pertained to Argentine beef. In late August 1914, a deal was done to guarantee monthly deliveries of 15,000 tonnes of beef to Britain, 80 per cent for the army, 20 per cent for domestic consumption. By spring 1916, 25,000 tonnes per month were being imported; during 1917, double that amount.

  Despite these bilateral agreements, Argentina continued to supply Germany with these commodities too, defying the blockade by shipping them to Holland and Scandinavia, from where they were then transported to the Fatherland. The Germans also had an extensive network of agents in Argentina who helped to maintain this trade and thwart economic cooperation with the Allies. Meanwhile, the return of unrestricted submarine warfare meant that Argentine merchant ships were now a legitimate target. Clearly matters were coming to a head.