The Secret War
Flying Pig
Flying Pig
During the Second World War, the Allies (and especially the British) had a large cadre of intelligence agencies which worked to make the task of the soldiers a lot easer. In most histories of that war, their importance has been underplayed; so here is a whole article devoted to them.
In the Field
Special Operations Executive was founded during the dark days following the surrender of France as a volunteer army to, in the words of Winston Churchill, set Europe ablaze. At the time of this statement being made, SOE only had a few operatives in action and no wireless communications. However, under the command of the civilian Hugh Dalton, the organisation revolutionised itself for the twin roles of subversion and sabotage.Subversion meant to foster revolution in the German Empire to try and either tie up the enemy soldiers or to cause whole nations to break out, and sabotage meant, broadly speaking, blowing stuff up. They took out bridges, trains and factories; seriously undermining the German war effort.
Churchill's orders seemed like an impossible task for the fledgling SOE as they were a tiny corps of agents against the mightiest empire ever to overtake the continent. However, they were determined to have a go at the Reich, and so in the November of 1940 they set up their Headquarters in Baker Street, London, in two family flats, and from there they began to fill in their ranks from men and women across the nation.The organisation expanded massively; senior officers came from the traditionally English class of Oxbridge and public school veterans but others came in from everywhere and all walks of life. SOE also bought up various properties across the UK from Scotland to the South; where the agents were trained for every possible eventuality; they were told how to kill unarmed, to derail a train, and to escape from handcuffs using only a pencil and a length of wire. If they survived the training and the pre-parachute course given to men of the Parachute Regiment, the elite fighting force of the UK, they were allowed to join SOE.
SOE was in many respects like the MI-6 of James Bond’s novels; at The Frythe, a secluded house in Hertfordshire, university graduates worked tirelessly to invent new weapons for agents to use. These included a single-shot pistol which looked like a cigarette, a submersible canoe and carbornudum; which was abrasive grease which could, if used correctly, stop a train. They also had a Camouflage Department in London, which worked on illusions made by theatre prop makers; for example what looked like a piece of camel dung may in fact be a landmine: truly gadgets that Q could have invented. On top of this they had the False Documents section, where agents were given their false identities, which included continental-style suits.
SOE was, however, not the only intelligence service in the UK. The existing branch of the intelligence service was called the SIS (now known as MI-6) and it thought that the ‘new kid on the block’ SOE was not only contemptibly amateur but, in the words of the SIS commander: “dangerous and bogus”. The SIS was in charge of gathering information for use by the services, and did not like the subversion and sabotage, nor the thought of SOE agents compromising their activities.
The SIS had many uses which were just as important; they were useful for sizing up the power and location of the enemy, allowing the generals to plan accurately, and they supervised the project, described later, to break the ENIGMA code and to distribute false information to the Germans. They had men in the employ of many high-ranking enemy people, who passed on vital information to SIS and thus the Allied armies.
SOE had another enemy in Bomber Command, one of the branches of the Royal Air Force (RAF) which dealt with the strategic bombing of Germany. They disliked the fact that they needed to loan out aircraft for missions which they saw as underhand; they wanted to win by killing Germans with bullets and bombs, not by sabotaging their military machine. Nevertheless, Winston Churchill (himself a former officer of the cavalry) liked having a James Bond-style agency around and felt that they could be useful, so they lived to fight another day.
With such high-ranking support, they needed to prove themselves, and they did not disappoint. First, in June 1941, they did the work of a whole bomber squadron by destroying the Pessac power station with a few explosive charges – which crippled work at a valuable U-Boat base in Bordeaux and halted the all-electric railways in that area. That mission epitomised field intelligence operations – small exertions of force at precisely chosen points to cause massive damage for minimal cost, without the enemy even knowing who did it.
They continued to baptise themselves in fire throughout the war: they carried out many missions all across the world, including planning the assassination of Reinhard Heydrich, who was a deputy to Heinrich Himmler in Czechoslovakia, by training his Czech assassins, blowing up a vital rail bridge in Greece which supplied Rommel’s army and blowing up the heavy water plant in Vermork, which ended the German plans to make an Atomic Bomb – maybe saving the war effort. Seeing as these operations often meant reprisals against the locals (5000 were killed in revenge for Heydrich) they liked to carry out ‘invisible sabotage’ – for example sending a tank-carrying train to the wrong place with just a forged letter, leaving no trace and implicating no-one.
Reading and Writing Enemy Information
During the war, German army and U-boat units used a cryptography machine called the Enigma, which comes from the Greek for a riddle. This was an attempt by the inventor and engineer Arthur Scherbius to bring the old, out-of-date German cipher methods into the new century with a mechanised version of the code wheel, which had many improvements on the original. The most important of these was that it had three (and later four) rotors; the letter was encrypted, then encrypted again, then again and one last time before being printed. This made the task of cracking the code a very difficult one.
The British first intercepted an Enigma message in 1926 and were baffled by it; it was like nothing that they had ever seen. The allied nations had a brief crack at it, but were completely confounded and so they gave up quickly, reasoning that they had no reason to fear the Germans in the wake of the Treaty of Versailles. However, one nation on the world stage was not able to relax – the new nation of Poland. They had been formed by the wrenching of old Germany into two; and they feared both German revenge and Russian attempts to invade and rule over them. They employed a disaffected former German soldier, Hans Thiolo-Schmidt, to get his hands on a military Enigma machine. This was made easier by the fact that his brother was Chief of Signals in the army; and had given him a job at the Enigma command centre. In 1931, Schmidt met with a French agent and allowed him to photograph two top-secret documents in exchange for DM 10000 – about $30,000 today. With the information in those two documents, the Allies were able to build their own, working machine. However, the French, for the reasons discussed already, did not make a machine of their own. However, they had an espionage agreement with Poland and so sent over their photographs; leaving the Poles to do the work.
The Poles knew that with four wheels, typing the same letter enough times would mean that it had the same value twice (if we have the formula n = 2n + t(mod 4) where t is the number of times that it has been written, then once t reaches 5 then (2n + t(mod 4)) will once more equal 2n + 1 – a repetition. This was pursued by a brilliant mathematician – Marian Rejewski.
I am going to dive into mathematics here; but Rejewski found tables of letters. The Germans typed a three-character sequence twice at the start of all messages, as Schmidt had found out, and so he could work them out thus: he knew that 1 and 4, 2 and 5 and 3 and 6 were the same input letter; so he could begin to work out the system.
He would find that two letters were related because they are in the same position in the key (if it was ASDHGF) then A and H are related, S and G; and D and F. If he had a message from the same day with any of the second letters in (H, G or F) as one of the first then he would note down what they were linked to, and so on until it got back to the first letter, so he may have got A > H > R > T (> A). He noticed that the chains changed each day, but nothing that he could do to the wires affected the length of the chains – so this was entirely down to the scrambler settings. Now he had a far smaller problem; instead of 10,000,000,000,000,000 combinations he was only concerned with 105,456 combinations since he did not need to worry about the plug board. So, over a year and using almost all of Polish Espionage resources, he set about categorising all of the chain lengths generated from each setting. With this in hand, he worked out the settings and then fed the message through a plug-board with no links – as if it was not there. He would then analyse phrases – so if he got wtrstndtnberltn then he would swap the t and the i around to get a new message which made sense – wir sind in Berlin. Through his awesome skill, Marian Rejewski had let the Polish government read all German correspondence. At one point the Germans changed the system, rendering all of Rejewski’s catalogues useless, but he fought back by building a mechanised way of finding the chains, which were basically six adaptations of the Enigma running in parallel; which he called the bombe.
However, in 1938, Rejewski finally hit the wall. The Germans added, possibly after working out that their messages were being read, two scrambler wheels and four cables – meaning that to crack messages the Poles would need to build bombes at a cost of fifteen times their budget for equipment. They had no hope of breaking Enigma again and so, two weeks before the invasion, the commander of the Polish security agency invited British and French spies over and gave them two replica Enigma machines and blueprints of Rejewski’s bombes. With this, even after Poland had fallen, there was still hope that one day Enigma might be broken.
The onus was now on the British to crack the cipher. They already had a strong anti-cipher establishment, called Room 40, which was populated by logicians and crossword addicts. The Poles had shown that mathematics was now an essential science in cryptanalysis, and so they contacted their friends in that field and moved on to a new establishment at Bletchley Park, in Buckinghamshire, run by the SIS. This was bigger than the original by far; due to the fact that the UK believed that two hundred million words would be intercepted from Germany every day.
With their massive resources, Bletchley could do far more than the Poles could ever have hoped to do. At first, they used the Polish methods, starting at midnight (when the codes were changed) and in a few hours being ready to listen into all German messages. Eventually they worked out a few tricks; the Germans had a keyboard like a modern one and so a great deal of codes would, say, be three-letter combinations (IOP, FGH, ERT and so on) or important three-letter combinations (GMU [God with us] or the initials of an operator’s girlfriend) so the men at the Park would try these first; and often they proved true.
Now, the entire method of de-coding the messages centred on the repeated key at the start of the message, and the British knew that it would not be long before the Germans worked out that this was a critical error. One man at the Park was tasked with working out how to work without these – Alan Turing. He worked out that the German messages had a definite structure, in particular that they always, at 0600 hours, sent out a weather report – so a message found at 0705 hours (taking account of time-differences) would almost certainly contain the word wetter, and since they were being sent by soldiers, he knew that the word was almost certainly always in the same place; normally it would read, say, wetter sonnig.
While this provided a guide to what the key was, the cryptanalysts still needed to work out which of a few it could be. Turing designed a machine to do this, which he christened the bombe in honour of the Polish machine. These were not, like a computer, automatic in entirety; you still needed a crib. The code breakers had a good trick to make sure that their cribs were correct; the machine could not encrypt the same letter as the same letter twice, so if you guessed that eryygh was wetter then you were wrong since there were two of the same letter in the ciphertext where there were two in the crib – so the Enigma’s two were not the same letter.
These bombes (there were, in 1941, 15 in total) provided vital intelligence especially in the Atlantic where merchant vessels were under constant fire from the U-Boat fleet which the Germans maintained. There, the messages helped greatly, but the British were keen to not allow the Germans to work out that they were reading their messages. Some of the U-Boats were allowed to go free, and to others the RAF sent a spotter plane, so that the Germans would assume that they had been the cause of the destroyer sent to clear up. Nevertheless, the intelligence proved crucial to winning the war in the sea, on land and in the sky.
During most of the war, Allied strategy relied on having the element of surprise over the Germans. However, Germany was rich and had a good espionage network; so the Allies knew that they would be able to get information from them. They turned to Sun Tzu for insipiration; he said that a commander should use agents given false information and allow them to be captured, which they did.
Before the invasion of Sicily, the Allies dropped a corpse in Spain, known as Operation Mincemeat, with plans for an invasion in Greece and Sardinia which made the Axis powers move their troops there; so the invasion went a lot more smoothly. The US also had a ghost unit which was designed to impersonate other units and so confuse the Germans; it used inflatable tanks and surplus uniforms and sometimes even went as far as mimicking slang.
All of this meant that for almost the whole war the Allies knew where the Germans were and what they would be doing and could make their plans in secret. In war the initiative is one of the most important advantages for an army; and the work of those behind the scenes meant that the Allies nearly always had this; they could warn units that were going to be ambushed and spring traps on supposedly hidden German units, and so without them the war would almost certainly have been lost. The field agents were also crucial; when the Germans looked on the verge of winning or makinga breakthrough they were on hand to throw a spanner into the works and set them back to the beginning.
