Authors: John Keegan
There were no survivors, as there had been none from
Monmouth
and
Good Hope
. With
Gneisenau
still energetically in action, the British could not pause to lower boats, and they swept on to leave whoever had not succumbed to fire and explosion to drown in the icy seas. Among the victims were von Spee and his sons.
Maerker, in
Gneisenau,
now had to defend himself against three enemies, the two battlecruisers and
Carnarvon
. His plight was hopeless, but he refused the call to surrender. The new German navy was trying to win a reputation for doggedness to equal that of the old mistress of the seas. At 6 p.m., as 200 survivors of the original 850 cheered the Kaiser, the sea overwhelmed the fireswept deck on which they stood, and
Gneisenau
turned over. The British ships rescued 190; Maerker was not one of them.
Kent
,
Cornwall
and
Glasgow,
the only ship to have fought in both the South American battles of 1914, rapidly overhauled the German light cruisers that von Spee had ordered to save themselves.
Leipzig
was sunk by
Glasgow
and
Cornwall;
her flag still flew, and only eighteen of her crew survived.
Nürnberg
was sunk by
Kent,
twelve of her crew were picked up but only seven survived exposure to the freezing Atlantic. Of more than 2,000 sailors in
Scharnhorst, Gneisenau, Nürnberg
and
Leipzig,
almost all had been killed or died in action. The balance sheet with Coronel was nearly exact.
Dresden,
for the moment, eluded her pursuers and was to remain beyond their reach for another three months. At first she hid in the maze of inlets that penetrate the Chilean coast above Cape Horn. Her captain waited in vain for colliers to resupply her. Eventually he went north into the Pacific, hunted by the British cruisers, which he evaded or outran. In early March 1915, however, the intelligence department of the Admiralty was sent an intercepted German telegram by an agent in Chile which, when decoded, revealed that
Dresden
was awaiting coaling off Coronel.
Glasgow
and
Kent,
co-ordinating their movements by wireless, eventually found
Dresden
at Más a Tierra—with Más Afuera it forms the island group of Juan Fernandez—on 14 March and closed. The German ship had only eighty tons of coal left and was at anchor, without hope of escape; a last wireless message from Berlin, relayed via Chile, had given Captain Lüdecke permission to seek internment. The British did not wait for the Chilean authorities to intervene.
Glasgow
opened fire and, though it was returned, inflicted in a few minutes sufficient damage to force Lüdecke to raise a white flag. As firing ceased, he sent a boat to parley for surrender, his object being to gain sufficient time to scuttle. By a bizarre coincidence, the officer he chose was Lieutenant Canaris, who, during the Second World War, was to direct the Abwehr, Nazi Germany’s military intelligence service. Luce, the captain of
Glasgow,
refused to negotiate, but Canaris won enough delay to allow flooding and explosive charges to send
Dresden
to the bottom. He and the surviving members of her crew were subsequently taken into internment by the Chilean navy.
The German cruiser campaign in distant waters was over—very nearly.
Königsberg,
which had never belonged to the East Asiatic Squadron, was to survive until July 1915, holed up in the swampy delta of the Rufiji River in German East Africa, where it would eventually be destroyed by the gunfire of two shallow-draught monitors,
Severn
and
Mersey,
directed by the observation of aircraft, the whole force having been sent from England at great expense and difficulty earlier in the year.
The cruiser campaign had never threatened to undermine Britain’s control of the seas. It had not even seriously damaged British maritime trade. The total of ships sunk by
Emden
and
Karlsrühe,
the most effective raiders, was thirty-two, gross tonnage 143,630; that was to be set against a total of nineteen million tons of British shipping plying the seas. Two of Germany’s armed merchant cruisers, the liners
Kronprinz Wilhelm
and
Prinz Eitel Friedrich,
had done almost as well, sinking 93,946 gross tons. The East Asian Cruiser Squadron proper had sunk no merchantmen at all.
Yet the German cruisers had caused serious alarm to the Admiralty and forced the diversion of very large numbers of warships to distant waters, away from the crucial areas of naval confrontation, the North Sea and the Mediterranean. Of the situation on 12 November, when
Inflexible
and
Invincible
were voyaging southward towards the Falklands, Winston Churchill lamented, “the strain on British naval resources in the outer seas was now at its maximum—a total of 102 ships of all classes. We actually could not lay hands on another vessel.” Admittedly, the total included many units that pre-dated the naval revolution, unfit to fight in home waters; but to it must be added French and Russian ships, and Japanese ships, if they were tied to the Pacific. If the maximum German commitment of cruisers to distant waters is reckoned at eight, the strategic return on the ratio was considerable.
Several British and foreign warships had been sunk,
Monmouth, Good Hope, Zhemchug, Mousquet, Zelée
and others damaged. The imperial convoys bringing Australian, New Zealand, Canadian and Indian troops to Europe had been delayed in sailing, and very many British and friendly neutral ships, carrying essential supplies, had been confined to port for fear of capture or sinking, in places as far apart as San Francisco, Rangoon and Calcutta.
Kreuzerkrieg
(cruiser warfare) could not be dismissed as a failure.
Yet it had failed in the end. The prestige of the Royal Navy, dented by Coronel, had been completely restored by the victory of the Falklands, while that of the young German navy had, after the brilliant episode of Coronel and the dashing exploits of the
Emden,
been peremptorily deflated. The Kaiser’s navy ended 1914 as it had begun: a service with a reputation to make.
Why had
Kreuzerkrieg
failed? The persistent need to coal, which limited the cruisers’ freedom of action, and the drag of accompanying colliers, was one reason; yet
Emden
had coaled only eight times and was never short. Indeed, shortage of ammunition, rather than of coal, may be thought the German captains’ real difficulty; after Coronel, von Spee’s magazines were half empty and, even had he managed to escape from the Falklands, he would have had insufficient ammunition to fight his way through to home if engaged by British ships in the Western Approaches or the North Sea. The failure to position ammunition ships, as colliers were positioned, may be thought a cardinal error by the German Admiralty.
In the last resort, however, cruiser warfare failed because the Germans could not conceal the movements of their ships. A steady stream of clues as to their whereabouts were picked up, often with great rapidity, sometimes in real time, and circulated with efficiency by the British between the Admiralty, local commands and pursuing naval units on the worldwide wireless and cable network. No delay, such as that which had afflicted Nelson, impeded the chase or obliged a return to base to pick up a lost scent—as after Nelson’s first visit to Alexandria.
There were failures. At the outset von Spee concealed his movements with great skill by observing wireless silence and listening to the transmissions of Allied ships that did not keep quiet;
Emden
was particularly skilful at evading HMS
Hampshire
in the Bay of Bengal by steering away from her call sign (QMD), made possible by listening for a weakening of the signal, an anticipation of direction-finding, which current technology did not yet permit. Von Spee was equally skilful, in the days before Coronel, by using a sole ship,
Leipzig,
to transmit and relay messages, thus disguising the size of his force.
38
Cradock failed to detect the deceptions. On the other hand, von Müller brought about his own downfall by his foolhardy decision to attack the Cocos and Keeling Islands, a quite unnecessary act, which ran him straight into the line of sight of the wireless station and provoked the transmission of perhaps the earliest ever piece of real-time intelligence of the electronic age, “strange ship in entrance.” It brought
Sydney
, with its superior 6-inch guns, down to the harbour in less than two hours.
Cradock was also incautious in the preliminaries to Coronel, his signals between ships revealing to the enemy the presence of his squadron, information amplified by messages from German agents ashore. His incaution was more than replicated, however, by von Spee, who chose to put his trust in inaccurate reports of the emptiness of Port Stanley harbour and then, for the sole purpose of destroying its not very important wireless station, steamed his squadron into a position dominated by the big guns of the British battlecruisers, which had arrived undetected, thanks to scrupulous observation of wireless silence, and from which the inferior speed and firepower of his ships allowed him no escape.
Strategically, the First World War, as a naval war, was to be dominated by the new invention of wireless. Coronel and the Falklands, unlike any other naval battles of 1914–18 though they were, belong to an emerging pattern. Before 1914 fleets at war operated in their search for each other as they had always done, working by line of sight and visual signal. After 1914, intelligence gathered by line of sight could be transmitted to infinite distance at the speed of light. Navies would take time to understand and implement the potentialities of the new technology. Yet it had altered for ever the nature of war at sea. Cradock and von Spee were victims of a failure to understand the new world, Sturdee a perhaps undeserving beneficiary. Less than thirty years after his victory, a new electronic dimension, radar, would almost eliminate the importance of line of sight. The Nelsonian world would have gone for ever.
CHAPTER FIVE
Crete: Foreknowledge No Help
T
HE WIRELESS WAR
of August to December 1914, in the far Atlantic and South Pacific, was the most dramatic intelligence episode of the Great War. Historians of the Eastern Front were later to suggest that Germany’s crushing victory over the Russians at Tannenberg, in east Prussia, in 1914 was brought about by Russian wireless laxity; Rennenkampf and Samsonov, the commanders of the invading Russian First and Second Armies, were accused of transmitting to each other the positions they intended to reach next day
en clair
(without encoding or enciphering their messages). More detailed research suggests that the Germans were guilty of equal laxity and that the cause in both armies was not carelessness but a lack of trained cipher clerks.
1
The course of the campaign of 1914 in the West is not held to have been affected by intelligence failures, since few important messages were sent by wireless; the French, using the Eiffel Tower in Paris as a transmitter, jammed German wireless comprehensively but without discernible effect. During the years of static warfare that followed, neither wireless messaging nor interference played any significant part, since the available equipment was ill-adapted to trench conditions and most communication, both strategic and tactical, was conducted by hand-carried paper, as was traditional, or by telegraph or telephone. Some overhearing, by erratic earth-conduction, was found to be possible, but its use was short-term and tactical at best.
Wireless interception by navies was of greater significance, although both the British Grand Fleet and the German High Seas Fleet became scrupulous at observing wireless silence. The British, ever on the alert for warnings of the Germans “coming out” into the North Sea, garnered every message that they could. On the only occasion, however, when advance warning might have made a difference, the
superbitas
of the Royal Navy’s traditional officer class robbed the fleet of advantage. The Chief of the Operations Division, Rear-Admiral Thomas Jackson, visited the naval intelligence division in the Admiralty, known as OB 40 (Old Admiralty Building Room 40) on 31 May 1916 to ask where its direction-finders (direction-finding had improved since 1914) placed the German signal DK, call sign of the German High Seas Fleet’s flagship. He was told, correctly, that the location was Wilhelmshaven and departed without explaining his reason for asking. Jackson was the sort of seagoing naval officer who did not share his thoughts with the non-combatant intelligence staff, composed as it was of such lesser beings as naval schoolmasters, university linguists and academic mathematicians. Had he explained why he wanted to know where DK was, he would have been told that the German flagship left its call sign at home when proceeding to sea, to disguise its movements, and adopted another. On the basis of his half-clever question, Jackson therefore telegraphed Jellicoe, commander of the Grand Fleet at Scapa Flow, to assure him that the High Seas Fleet was still in harbour. As a result, Jellicoe eventually heard that the Germans were “out” from Beatty, commander of his battlecruisers, which had been sailed south on other information. He was then at sea himself, but making less than best speed in order to conserve fuel, so that he was late meeting the enemy battleships off Jutland, late fighting the battle and late cutting off their retreat. Admiral Jackson’s disinclination to take the codebreakers into his confidence robbed the Grand Fleet of a major opportunity to scupper the German navy for good.
2
Jackson was exceptionally arrogant. A Royal Naval Volunteer Reserve lieutenant, W. F. Clarke, belonging to the OB 40 staff, recorded that he “displayed supreme contempt for [our] work. He never came into the room during [my] time there except on two or three occasions, on one of which he came to complain that one of the locked boxes in which the information was sent him had cut his hand, and on another to say, at a time when the Germans had introduced a new codebook, ‘Thank God I shan’t have any more of that damned stuff.’ “
3
There were many like Jackson, however, if not so bad, and it would take nearly a generation to pass before operations officers would begin to accept that most “raw” intelligence was only as good as the interpretation put on it, often best supplied by the intelligence officers who gathered it on a day-to-day basis.
OB 40 also had its admirers, and rightly so. It began to supply crucial information almost from the start, including forewarning of the raid on the English east coast towns of Scarborough, Hartlepool and Whitby on 16 December 1914.
4
Had it not been for a visual signalling error committed by Beatty’s flag lieutenant—who was to repeat his mistake on three later occasions, at Jutland with disastrous effect—the Scarborough raid might have resulted in the destruction of the German battlecruiser force.
5
OB 40 had only then been in existence since 8 November and had been brought into being because of an intelligence windfall. In late October the Russians had delivered to the British a copy of the main German naval codebook (SKM) and a collection of square-ruled charts, used to denote sea areas. They had been recovered from
Magdeburg,
a German light cruiser lost in the Baltic on 26 August. OB 40 subsequently acquired the codebook used for communication between German merchant and naval ships (HVB), found in a German steamer interned in Australia early in the war. Finally, it got possession of a codebook used by German senior officers (VB), allegedly dredged up in the nets of a British trawler off Holland on 30 November, at a spot where four German torpedo boats had been sunk on 17 October.
6
It was with this material, and intercepts collected via a hastily established chain of coastal listening stations, that OB 40 went to work. They were aided by the Germans’ very free use of wireless—forced upon them in part by the dragging up of their oceanic cables by the British cable ship
Telconia
on 4 August 1914—but above all by the nature of the means the Germans used to disguise their signals.
Secret writing takes two forms, known to cryptologists respectively as codes and ciphers. Cipher is a method hiding meaning by altering the form language takes, either by “transposition” or “substitution.” Transposition, a technique so ancient that there is no record of its origins, works by changing the order of letters; the simplest system, familiar to any cipher-minded schoolboy, is to shift once along in the alphabet, so that A becomes B, B becomes C and so forth. “The cat sat on the mat” is thereby recorded as “UIF DBU TBU PO UIF NBU”; the result is unlikely to baffle an interceptor for any length of time. There are many ways of complicating a message in transposition cipher; one of the simplest is to run the letter group together—UIFDBUTBUPOUIFNBU—to disguise the word length, but it provides little protection. Another, more sophisticated, is to shift two or three or ten letters along in the alphabet; while straight transposition underlies the ciphering, however, the iron laws of “frequency analysis” will yield the solver a way in. The law of frequency reveals that, in English, E is the most commonly written letter, followed by A and so on. Frequency tables, known to all cryptologists, provide a ready means of decipherment. Frequencies are different in other languages—Z, rare in English, is common in Polish—but the tables cannot be defeated.
Not, that is, unless complexities are introduced. Cryptographers—those who write ciphers or codes—have devised many complexities. Perhaps the best known, and most difficult, is the alphabetical grid, which arranges the twenty-six letters of the Roman alphabet (reduced to twenty-five by combining the letters I and J) in a square five letters wide and five deep, and numbers the columns. If A is the first letter in the top left-hand corner, it is rendered as figures 11, and so on to Z as 55. At its most elaborate, known as a Vigenère, after its sixteenth-century French inventor, the square is twenty-six by twenty-six, presenting a frequency problem of great difficulty. It is not insurmountable, though it was long thought to be so.
7
Further complications may be devised, particularly when cryptographers begin to use figures rather than letters in transposition. There developed, during the seventeenth century, a strange halfway house between transposition and its cipher alternative, substitution, in which, for example, King Louis XIV’s principal cryptographers, the Rossignols father and son, rendered whole words into mathematical figures. The technique had been anticipated by numbering common French “digraphs,” e.g., QU, OU, DE, but the Rossignol system, known as the Great Cipher, defeated everyone; it was only unlocked, long after the meaning of the messages in which it was written had ceased to have importance, at the end of the nineteenth century.
By then, however, cryptologists were on the brink of instituting a new cipher system altogether, employing full-scale mathematical “substitution” for letters. Mathematical substitution appeared to promise true impenetrability since by addition or subtraction, a numerical message could be so varied that a cryptanalyst—who attacks secret writing—would simply be defeated by time; but as long as the intended recipient possessed the “key” to understanding the chosen mathematics, it could be read at the other end.
Keys were the problem: how to ensure that senders and recipients possessed the same set, how to deny keys to the enemy? The simplest solution was to write the keys in a book, logically arranged, which could be owned by all legitimate parties. Codebooks were widely in use during the eighteenth century, if only to disguise the more important words in a message, for example, the proper names of people, places, ships and so forth, the rest being left in plain language. Major Benjamin Tallmadge, George Washington’s chief of intelligence after 1778, devised a codebook out of
Entick’s Spelling Dictionary
by taking from it the most frequently used words, numbering them in alphabetical or numerical order and adding random words for those not listed. He also chose sixteen numbers for key individuals and thirty-six others for cities or places. Tallmadge kept the original, sent another copy elsewhere and the third to George Washington. It cannot have disguised much from the British if a letter of 15 August 1779 is a fair sample: “Dqpeu [Jonas] beyocpu [Hawking] agreeable to 28 [an appointment] met 723 [Culper Jun.] not far from 727 [New York] and received a 356 [letter].”
8
This amateurish example discloses the principal weakness of a codebook: that, by collecting the words used, from messages intercepted, parts of the book can be reconstructed; if enough material passes through the hands of the enemy, it can be reconstructed in its entirety.
An apparent safeguard is to avoid the use of the alphabet altogether and employ only figures, singly or in groups. By the beginning of the nineteenth century the British were doing just that. A message from William Drummond, British emissary to Denmark, to the Foreign Secretary, Lord Grenville, in 1801, on the eve of the Battle of Copenhagen reads, in its last sentence, “3749 2253 529 2360 1268 2201 3356,” which stands for “Count Bernstorff does not even affect to conceal his alarm and inquietude.”
9
The protection, however, is not as great as seems, even though, in the original, there is no indication of sentence length, nor do the groups betray word length. But by painstaking accumulation, again, watching for repetitions, and by guesswork, the codebook can be reconstructed and meanings deduced.
From the use of all-figure codes, it was but a short step to a much more secure system, technically known as “super-encipherment.” It employed two—or more—keys: the codebook itself and a system of figure alteration, by addition or subtraction. Since the groups thus altered did not coincide with those in the book, and did not obviously repeat themselves, retrieval of meaning became much more difficult. Yet not impossible: there was an underlying logic, supplied by the second key, which might be established by mathematical analysis. German diplomatic telegrams were, during the First World War, commonly super-enciphered. Oddly the most famous, the Zimmermann telegram, was not. Broken by Room 40, its contents—which encouraged Mexico to attack the United States—prompted President Wilson’s declaration of war on Germany.
Many other methods of complexifying secret writing had been devised by the beginning of the twentieth century, many of them variations on the Vigenère square. The most ingenious was invented by an American army officer, Major Joseph Mauborgne, in 1918. It came to be known as the “one-time pad” and was indeed unbreakable. A Vigenère square was constructed in two copies, one held by the sender, one the receiver. It gave the key to the enciphered message; once used by both parties, it was destroyed. One-time pads protected messages absolutely because the coincidence between cipher and plain text was entirely random and the absence of repetition, assured by destruction, forbade all chance of frequency analysis, or any other method favoured by cryptanalysts.