Intelligence in War: The Value--And Limitations--Of What the Military Can Learn About the Enemy

by John Keegan

  The vastness of the sea, the variety of its weather and the multiplicity of hiding places offered by its coasts and islands have always imbued precise intelligence of the enemy with the highest value in naval warfare. Fleets can disappear, single ships can navigate vast distances without ever being seen by another; indeed, in the months before Pearl Harbor, a Japanese ship was deliberately sailed down the planned course of the attack fleet from the home islands towards Hawaii and met no other vessel during several weeks at sea. It is therefore not surprising that Nelson lost Bonaparte’s fleet, several hundred strong though it was, in 1798. Anyone who has sailed the Mediterranean, a comparatively small sea, knows how long are the periods in which no other ship is seen. It is only in the vicinity of ports that companion vessels appear and they are soon sunk below the horizon by a change of course. Even coastwise sailing, the traditional means of passage in the inland sea, can be lonely. Headlands, peninsulas, islands intervene readily between one vessel and another and they are quickly lost to one another.

  Nelson’s loss of touch with Bonaparte’s Egyptian invasion fleet, after his dismasting in the storm off Toulon, and failure to regain it, is therefore quite explicable. There were several persuasive destinations the French might have chosen, including Ireland, Spain, Naples, Constantinople and Anatolia (Turkey), as well as Egypt. The routes thither might be subsumed into two, west and east, which were mutually exclusive. Nelson took a risk, but a lesser one, in discounting the western option. Having correctly decided that Bonaparte had sailed east, a decision based not merely upon a judgement of probabilities but on the human intelligence available, including commercial agents’ reports as well as gossip and rumours from within the orbit of French influence in Europe, his method of running the fugitive fleet down was quite logical. He went from place to place, searching hiding places, questioning ship captains and following up reports. His justifiable anxiety to keep Bonaparte out of Naples and Sicily led to his being foxed when the French fell on Malta; he then not only got on the trail again but got ahead of the quarry, overrunning the invasion fleet at night and arriving at Alexandria before it. His mistake, in a campaign dogged by intelligence famine, was not to wait there but, in a fever of reconsideration, to retrace his course until he picked up firm intelligence at a place which he had already visited.

  The value of any study of the Nile campaign to a modern intelligence officer is to illustrate how much better provided he is than a commander of the pre-cable, pre-wireless age. Even with the telegraph and wireless, it would prove possible, as the lamentable tale of the pursuit of the Goeben and Breslau in August 1914 shows, to let an enemy get clean away. It is inconceivable, however, that Nelson could have lost Bonaparte had the Royal Navy had the signal resources available to it in the Mediterranean even sixty years later. The simplest cable system would have ensured that Nelson waited at Alexandria on the first visit and so brought the campaign to an end. Indeed, the same result could have been achieved with the resources then available, had they been in place. Had the British maintained a network of agents around the Mediterranean coastline, and kept despatch boats at friendly or neutral ports—say in Naples, Sicily, Malta, Turkish Crete and Cyprus, something not beyond the power of diplomacy to achieve, particularly with money to grease local palms—Nelson would not have had to lament his want of frigates or to use his battle fleet also as an instrument of reconnaissance. The lack of an intelligence network in the Mediterranean was, however, the outcome of a sudden surge of French power, which put weak local states in fear and perhaps was not to be reversed without a major British naval victory; which is to say that the achievement of earlier success in the campaign of the Nile depended upon fighting an earlier battle. There, precisely, was Nelson’s difficulty: no intelligence, no battle. Hindsight solves Nelson’s intelligence problem. In the circumstances, he did no worse than realities allowed. In a big sea, with slow ships, chasing a vanished enemy was bound to be a time-consuming business.

  The vastness of the ocean also defined the circumstances in which the British fought the U-boat war. The first episode, in 1915–18, which actually brought Britain nearer starvation than the second two decades later, was eventually terminated, not by intelligence process, not by offensive methods, but by an exercise in operational analysis: a clear-thinking junior officer perceived that the formation of convoy would contain the sinking of ocean-going merchantmen within bearable limits, a notion previously rejected by the Admiralty. So it proved; sinkings declined, even though contemporary escort vessels had but the most primitive acoustic search equipment and crude anti-submarine weapons. The beginning of the second U-boat war in 1939 found the Royal Navy equipped with an active underwater search device, Asdic, later to be known as sonar, but with anti-submarine weapons scarcely improved since 1918. Moreover, the number of available escorts had declined relative to the number of essential merchant-ship sinkings. As a result, large weakly escorted convoys suffered heavy losses from the outset of hostilities. The Admiralty sought to reduce losses in a number of ways: by an accelerated programme of escort building and improvisation; by diverting aircraft from the bombing campaign to maritime escort and surveillance duties, a diversion always resisted by the RAF; by improving anti-submarine weapons and search equipment; by mining the approaches to the U-boat ports and by anti-U-boat intelligence. The intelligence campaign sought to protect convoys by diverting them away from identified U-boat positions and by directing escorts—both surface ships and anti-submarine aircraft—against individual U-boats. The principal intelligence means were radio direction-finding and the decryption of signals both from U-boats to base and vice versa. Not until May 1941, however, did Bletchley break into the U-boat traffic and its successes were offset by that of the German B-dienst, which read the British convoy code for most of 1942, and by periods of blankness, brought on by German alterations of procedure or machinery in the operation of Enigma.

  Despite all intelligence difficulties and failures, rerouting of convoys was a success; only a minority of convoys were attacked and, during the long periods of bad weather that prevail in the North Atlantic winter, the U-boats often could not form wolfpacks or patrol lines, nor find convoys even when directed towards them from base.

  In the last resort, however, the U-boats were defeated neither by Anglo-American intelligence success, nor by the eventual failure of the B-dienst’s decryption campaign, but by battle at sea. By the spring of 1943 the combination of many new or improved measures taken by the Allies had set terms of engagement which the U-boats could not overcome. Continuous direct aerial surveillance of the convoy routes denied U-boats the freedom to cruise undetected on the surface; aggressive aerial patrolling of their exit routes from the French Atlantic ports to the high seas sank many and forced all to make their passages to war stations submerged at laboriously low speed; close protection of the convoys by escort aircraft carriers drove attacking U-boats down and resulted in frequent sinkings of those that surfaced; the multiplication of escorts, better trained and equipped to carry out group attacks, sank U-boats which found firing positions; improved radar and radio direction-finding led escorts to U-boats hovering around convoys beyond line of sight. In the end, as Dönitz was forced to admit to his own men, the balance of advantage swung so sharply against the U-boats that the German submarine fleet could be saved from destruction through attrition only by its withdrawal from the scene of action. The Battle of the Atlantic did indeed eventually become a true battle, a great naval battle extended in time and space, which was won by the Allies.

  The battle against the German V-weapons was, by contrast, a real intelligence battle, in that it was intelligence that alerted the Allies to the threat and intelligence in all its forms—human, signal and imaging—that provided the beginnings of the antidote, but it ended in no such clear-cut victory. The advantage for the first four years of the Second World War ran wholly the Germans’ way. Having begun to construct an extra-atmospheric rocket, capable of carrying a warhead, well before the
war began, the German army had succeeded by late 1942 in solving most of the problems of launching and propelling it in flight and guiding it to its destination. Spurred into competition by the rocket programme’s success, the German air force had meanwhile developed and largely perfected a cruise missile. Both weapons were greatly in advance of their time, measured against weapon development on the Allied side, where they had no counterparts.

  From an intelligence point of view, the main aspect of interest aroused by the V-weapons is the difficulty the Allies encountered in taking the measure of the threat and then in deciding what counter-measures should be mobilised against it. To the lay mind, what impresses about the world of science are the openness of the scientific practitioner to new ideas and the readiness of the scientist to set aside prejudice in pursuit of fresh knowledge. Science, the layman believes, is the arena of rationality, unfettered by fixed beliefs, populated by pure intellectuals ever prepared to reject convention and depart upon a free voyage of experimental and theoretical discovery. The history of science contests that optimistic view at almost every turn. Scientists can be as prejudiced as theologians, particularly so if their pet theories are contested. No modern scientist in an influential position showed himself more prejudiced than Winston Churchill’s personal scientific adviser, Professor Lindemann, whom the Prime Minister had had created Lord Cherwell. He had taken the view that long-range military rockets could work only if propelled by solid fuel, which dictated that they should be of enormous size and need highly conspicuous launch pads. He absolutely rejected the suggestion that the theoretically more compact liquid fuel could be confined and controlled as a propulsive medium. He had the mathematics to prove his point of view, and so strongly did he hold it that he used his privileged position to deride and attempt to discredit scientists junior to himself in the official hierarchy who argued the contrary.

  He was, as events would painfully show, quite wrong but the evidence necessary to disprove him took precious months to accumulate. Eventually only the presentation of incontestable photographic evidence of the existence of rockets and then pilotless aircraft, later supplanted by eye-witness reports of their flight and finally by the delivery of physical fragments of the objects, drove him into admission of error. By then, fortunately, his opponents had won a hearing sufficiently strong to lead the British Chiefs of Staff to authorise a raid designed to obliterate the V-weapons centre at Peenemünde. It did not altogether achieve obliteration; it certainly did not achieve the extinction of the leading V-weapon scientists, which was one of its primary objects. Nevertheless, it set the secret weapons programme back and the delay, enhanced by the final difficulties the Germans encountered in bringing the V-1 and V-2 to an operational state, postponed their delivery against British targets beyond the opening of the D-Day invasion. This ensured that their launch sites would soon be overrun, thus negating the German expectation of postponing defeat by long-range bombardment of the invasion forces’ points of departure.

  The V-weapons programme has interest from another intelligence aspect—the unusual preponderance of human intelligence in influencing opinion on the other side. Human intelligence played almost no part in determining the conditions under which most of the campaigns which form case studies in this book were fought. Its importance, though paramount in the Nile campaign, when Nelson was acting as his own intelligence officer, and crucial to Stonewall Jackson in the Shenandoah Valley, was negligible during the U-boat war and quite insignificant during the campaigns of Crete and Midway. Paradoxically, in the high-technology struggle between German secret weapon scientists and their blinkered Allied opponents, human intelligence was of critical importance. The unattributable Oslo Report gave the first clue; eavesdropping, if that was what it was, by the unnamed “chemical engineer” later provided the trigger to Allied action. Thereafter, though photographic intelligence, imagery as it would now be called, supplied the earliest confirming substance, agent reports from foreign workers at Peenemünde and observations by the Polish underground provided the direct evidence that the V-weapons were actually airborne. Without those reports, and the evidence supplied by Swedish neutrals, including the sea captain with his watch, London would have lacked the picture—fairly clear as it eventually became—of what the hazily defined menace of flying bomb and supersonic rocket ultimately threatened. The intelligence attack on the V-weapons kept alive the importance, elsewhere so greatly discredited, of humint.

  Humint, though the term was then unknown, also supplied the means, directly and indirectly, by which Jackson so successfully conducted his campaign against superior odds in the Shenandoah Valley in 1862. That campaign, in any large-scale military perspective, hovers uncertainly between the old and the new. In contemporaneous terms, Jackson belonged to the future, the future of the electric telegraph and the railway alongside which it usually ran. Practically, neither telegraph nor railway played anything but a tangential part in Jackson’s manoeuvring. Although he eventually withdrew his Valley army to Richmond by railway, he scarcely used it to manoeuvre during his campaign of bewitchment and bewilderment; his employment of the telegraph, as a means of communication within the Valley and from it to higher command elsewhere, was intermittent. Jackson in the Valley behaved as a trusted Napoleonic subordinate might have done, superior though he was in talent to his Confederate seniors; he made his own appreciations, asked for no orders, and based his decisions on his own intelligence assessments, founded on close and local observations.

  Like a pre-telegraphic and pre-railway commander, Jackson was most concerned to understand the geography of the theatre in which he was operating and to use it to his advantage. A man with an intuitive sense of ground himself—in that respect he resembled that other taciturn, relentless, hard-fighting general of the war, Ulysses S. Grant—he was greatly served by his mapmaker, Jedediah Hotchkiss, a gifted, if self-taught cartographer. In the modern world, where images of every sort abound, it is difficult to visualise the difficulties of travellers and voyagers of an earlier time, when often the only picture available of the route forward was held in the head of a fellow-traveller who had gone that way before or of a local unaccustomed to explanation. Since America east of the Appalachian chain had been settled, or at least explored and travelled, for 200 years before the Civil War’s outbreak, it may seem extraordinary that much of its terrain was unmapped and indeed unknown to strangers. Such was, nevertheless, the case. Though there were turnpike roads in the Shenandoah Valley, and railroads that ran into it, the Union armies lacked maps of its topography, which was unknown in detail to their officers. Jackson, a West Virginian by upbringing, knew the outlines of the topography, but he took trouble to master the details by requesting Hotchkiss to survey the theatre and make him a military map of its most important features, particularly waterways, bridges and passes through the high ground. It was Hotchkiss’ map that gave him his advantage. Jackson’s succession of small, local victories, which frustrated the manoeuvres of his opponents, superior in numbers as they always were, was not the outcome of chance or recklessness but of careful calculation. He was his own intelligence officer, as Nelson had been during the Nile campaign, with the difference that, though similarly confined within a narrow zone of operations, his role as a fugitive, not a pursuer, was to mislead, confuse and avoid a decisive confrontation, rather than bring his enemy to a battle of annihilation.

  All the cases studied in this book concern military intelligence in the strict sense: how the use of intelligence brought the enemy to battle on terms favourable to the intelligence victor (the Nile, the naval battle of the Falklands, Midway, the U-boat war) or spared the intelligence victor battle on unfavourable terms (the Valley); or else how the successful practice of intelligence nevertheless failed to avert an unfavourable outcome (Crete, the V-weapon campaign). Its purpose is to demonstrate that intelligence, however good, is not necessarily the means to victory; that, ultimately, it is force, not fraud or forethought, that counts. That is not the currently fa
shionable view. Intelligence superiority, we are constantly told, is the key to success in war, particularly the war against terrorism. It is indisputably the case that to make war without the guidance intelligence can give is to strike in the dark, to blunder about, launching blows that do not connect with the target or miss the target altogether. All that is true; without intelligence, armies and navies, as was so often the case in the age before electricity, will simply not find each other, at least not in the short term. When and if they do, the better informed force will probably fight on the more advantageous terms. Yet, having admitted the significance of the pre-vision intelligence provides, it still has to be recognised that opposed enemies, if they really seek battle, will succeed in finding each other and that, when they do, intelligence factors will rarely determine the outcome. Intelligence may be usually necessary but is not a sufficient condition of victory.