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

by John Keegan

  The exit strategy was to fight, and between 8 and 12 June, the Valley Army fought with terrible ferocity. The action of 8 June, conducted in the streets of Port Republic itself, was brought on by an uncharacteristic failure of attention on Jackson’s part. Tired himself, from days of marching, and with a tired army, he allowed the need for rest to overcome watchfulness. On what was hoped to be a peaceful Sunday morning, Federal cavalry got into Port Republic and surprised the sleepy Confederates. They were chased out with only difficulty and loss. Meanwhile, Frémont’s army, advancing above the South River in strong but unsynchronised support, was defeated at the village of Cross Keys.

  Jackson might now have used the time he had won to break contact and retreat in haste to Brown’s Gap, the railroad and Richmond. That was what prudence dictated. Instead he decided to engage the enemy again, in the hope of inflicting a conclusive victory but at the risk of falling into a final trap.

  The trap almost closed. The jaws were kept apart only by the harshest of fighting on two fronts, at right angles to each other. On the high ground north of the Shenandoah’s South Fork, Frémont was held at bay, while on the low ground between the river and the Blue Ridge the bulk of Jackson’s Valley Army, recovering from initial disorganisation, eventually formed a strong point and drove Shields back. In several hours of fighting in the early morning of 9 June, the heaviest of the whole Valley campaign, the Confederates eventually drove both Frémont’s and Shields’ men from the field, at a cost of over 800 killed and wounded to each side. A Confederate survivor later recorded, “I have never seen so many dead and wounded in the same limited space.”30

  The Valley Army was nevertheless the unquestionable victor of these culminating battles, so much so that Frémont and Shields did not merely leave it in possession of the battlefield, traditionally the mark of defeat accepted; each peremptorily withdrew northwards into the Valley, to positions from which neither could resume an offensive. After their defeat at Port Republic “[they] were terrified of the Valley Army. On June 19, with the rebels seventy miles away, Banks fretted that they were upon him.”31 In the face of such moral feebleness, Jackson actually re-entered the Valley, from his positions beyond the South Fork, and rested and refitted while the enemy retreated.

  There was even in mid-June a revival of the suggestion that he should march northwards into Pennsylvania, opening an invasion of the North. Lee, now in overall command of the Army of Northern Virginia, organised reinforcements to send him and took no trouble to disguise the disposition from the enemy. It was, in truth, no more than a feint. The Confederacy, at a high crisis of its existence, was not really ready to take war to the enemy. It needed to assure the security of its own capital, not to menace that of its enemy. On 13 June Lee noted on a letter from Jackson, “I think the sooner Jackson can move this way [to Richmond], the better. The first object now is to defeat McClellan. The enemy in the Valley seem at a pause. We may strike them here before they are ready to move up the Valley. They are naturally cautious and we must be secret and quick.”32

  Lee, in short, had decided that he needed Jackson on the Virginia Peninsula, where the bulk of the Union Army was now deployed. On 16 June, therefore, he sent orders for Jackson to bring the Valley Army to the vicinity of the Confederate capital. Jackson departed on 18 June, riding ahead to meet Lee near Richmond on the afternoon of the 23rd. His army, following behind, crossed the Blue Ridge Mountains and arrived at Richmond shortly afterwards, to take part in the Seven Days Battles, which brought McClellan’s Peninsula Campaign to defeat. Richmond was saved and so, for a time, was the Confederacy.

  In the second half of 1862 and during 1863 the Confederacy, under Lee’s generalship, went over to the offensive, which culminated in the Union’s flawed victory at Gettysburg. The progressive destruction of the South’s defences followed. What part had Jackson and his intelligence operations played in the postponement of the South’s defeat?

  Jackson, first of all, had worked on the uncertainties and anxieties of his opponents, at every level from the field commanders to President Lincoln in Washington. He had threatened Frémont and Shields with defeat in open battle in the theatre of the Valley. He had also menaced Lincoln with the danger of an advance across the Potomac to Washington itself. Secondly, within the Valley theatre, he had confronted each of the Northern armies in turn, drawing them deeper into the Valley at the outset of the campaign, when the need to distract Union strength from the Peninsula was paramount, later risking battle when it could not be avoided but almost always on his own terms. He had tried his own army hard—his “foot cavalry” achieved, as its endurance increased, almost unparalleled feats of marching, at times covering as much as seventy miles in a hundred hours—but those who could stick the pace remained able to fight even at the end. Losses from disease and exhaustion ran as high as 30 per cent but battle casualties were surprisingly low, only about 2,000 in forty days of fighting. When it left the Valley, the army, which had admittedly been reinforced, was actually larger than when it had begun the campaign.

  Jackson’s success was due in large measure to his ability—reinforced by his natural taciturnity and secretiveness—to think faster and more clearly than his opponents and to calculate more moves ahead, making good choices, rejecting bad. That ability rested, however, on his possession of superior knowledge of the Valley’s geography and of superior local intelligence, constantly refreshed by the work of a busy intelligence chief, Jedediah Hotchkiss, and a friendly population. The best generals have always valued detailed knowledge of topography, almost above any other sort of intelligence. Jackson was a better general than any of his opponents, and his operations in the Valley, assisted by McClellan’s refusal to profit by any of the advantages the North’s material superiority gave him, assured the successful defence of Richmond and the Union setbacks of 1862–63 which flowed from McClellan’s retreat. The proof of his generalship was demonstrated above all, however, by his exploitation of the secrets of place and passageway in the complexity of the Shenandoah Valley, which he possessed and the enemy did not. He deserved his triumph.

  CHAPTER FOUR

  Wireless Intelligence

  THE USEFULNESS of intelligence had been limited since the beginning of warmaking by the carry of voice, range of vision and speed of message-carriers. No amount of ingenuity could eliminate the delay. The Nelsonian navy had devoted much ingenuity to minimising it. By 1796 a system of fifteen inter-visible semaphore stations had been built between the Admiralty in London and the port of Deal, through which a message could be sent and acknowledged within two minutes; by 1806 the chain had reached Plymouth, transmission and acknowledgement, along a distance of 200 miles, taking three minutes. The system, which depended on each station being able to see the semaphore arms moving on the one before, worked only in daylight, however, failed in fog and shut down earlier in winter than summer.1

  Mechanical semaphoring, moreover, like flag signalling, could send only such messages as were prearranged by book code; but by the 1840s the American Samuel Morse had devised his code, technically a cipher, which allowed messages to reproduce speech, by allotting each letter of the alphabet a separate identity in the form of short or long symbols, single or combined, soon to be known as “dot” and “dash.” When translated into electrical pulses and transmitted along a metallic cable, a method of communication pioneered by the Englishman Charles Wheatstone in 1838, delay in signalling was eliminated. The first successful electric telegraphic Morse code messages were passed in 1844, between Washington and Baltimore.

  The electric telegraph rendered mechanical systems almost instantly redundant. The Admiralty sold off its stations, which are remembered today only in such place-names as “Telegraph Hill” or “Semaphore House” in England’s southern counties. Yet the electric telegraph did not immediately establish instantaneous communication between commanders and subordinates. For one thing, deficiencies in power supply required frequent retransmission in the early telegraphic links; during t
he Crimean War, though London was connected to Balaclava by an early undersea cable, messages still took as long as twenty-four hours to arrive at expeditionary headquarters, because of the need to relay at several stages.2 Secondly, local commanders found interference from above tiresome, and sometimes chose to ignore instructions. Thirdly, the system was inflexible, as it would remain until the invention of a method of electronic communication not dependent on cable, literally “wireless.” Commanders who were moving about in the theatre of operations, or otherwise absent from cable head, could not be contacted, nor could they signal in return.

  Cable communication, had it then existed, might have benefited Nelson during the Nile campaign, but only when he touched land and only if the cable head had been in the hands of friendly operators. As he was usually at sea, in pursuit of an enemy who chose not to be seen, it is difficult to identify the moments when he might have been helped. Had there been a link between Alexandria and southern Turkey, and had it operated in his favour, he could have saved himself his second transit between Egypt and Sicily and caught the French perhaps a month earlier; but that is a big if. The movement of the French fleet was a model exercise in evasion, likely to have succeeded in any age before the development of wireless, aerial surveillance or radar.

  Jackson, operating in the telegraph age, did not much benefit by it. Nor did his enemies. Neither side was helped by the telegraph links which reached into the Shenandoah Valley, at least in the theatre of operations. The Confederates destroyed them in retreat, as they did the railroad track, while their own link to Richmond seems to have had gaps; certainly in the confusing days of order and counterorder, in early June, communication between Jackson and Lee seems to have been carried on largely by letter, at several days’ delay.3 Not until Grant, a master of telegraphic method, took command of the Union armies in 1864 would the telegram come to dominate in the management of armies; and, even then, it remained a strategic, not tactical instrument, again because of the rigidity of the network and the infeasibility of pushing the cable head forward into the maelstrom of battle.4

  The invention of wireless, requiring only transmitter, power source and receiver to work, and using the atmosphere itself as the carrying medium, in theory ushered in an era of free communication; but at first in theory only. The concept of wireless was first proposed by a British physicist, James Clark Maxwell, in the 1860s; he predicted that electromagnetic waves could be propagated in space and would travel at the speed of light. In 1888 the German scientist Heinrich Hertz published the result of experiments which actually demonstrated electromagnetic wave propagation—and reception—though only over distances of a few feet. By the 1890s, however, following the suggestion by Sir William Crooke that electromagnetic waves could be used for communication, several practical men were building and using “wireless sets.” One was a Royal Navy officer, Captain H. B. Jackson; another was an Italian, Guglielmo Marconi.

  Jackson’s experimental career was blighted by postings to conventional appointments; it may be, in any case, that he was not a true visionary. Marconi was, though, of the entrepreneurial rather than the pure scientific sort. Very early he grasped that the applicability of wireless lay at sea. He was working in the era of the great European naval race, when the adoption of Germany’s Naval Law of 1900 had launched it into direct and deadly competition in battleship building with Great Britain. It was also an era of great expansion in maritime trade; the number of steamships plying the ocean had recently exceeded that of sailing ships for the first time. The great majority, nearly 9,000, sailed under the British flag, a principal reason, beside that of preserving control of the seaways within its enormous and worldwide empire, for Britain’s determination to maintain its naval supremacy.

  Marconi saw that wireless offered the promise of a great improvement in signalling at sea, both between ships and from ship to shore. Ship owners would certainly pay to equip their merchantmen with wireless, if only at first on the larger vessels and passenger liners; but the real scope for commercial exploitation lay with the war fleets. No navy could afford to be left behind in what would as certainly become a race as that over speed, armoured protection and calibre of guns. First, however, wireless actually had to work. Despite relentless experimentation in the mid-1890s, Marconi could not achieve reception at ranges above ten miles. The waves propagated, moreover, could not be tuned, and so blanketed the whole radio spectrum. The receiver could not distinguish between propagated waves and “atmospherics,” and if two stations transmitted at once the result was a jumble of unintelligible marks on the tape of the telegraph inker, which was as yet the only mechanism on which signals could be represented.5

  Between 1897 and 1899, however, Marconi so much improved his apparatus that by 1900 the British Admiralty had decided to adopt wireless as a principal means of communication, had accepted Marconi’s hard-headed commercial terms and had purchased fifty sets, forty-two to be installed in ships and eight in shore stations along the south coast, from Dover to the Scilly Islands. The range achieved exceeded fifty miles, and intelligible messages were passed at ten words a minute. Improvement then accelerated at an astonishing pace. In December 1901 Marconi succeeded in signalling between Cornwall in England and Cape Cod in the United States and in January 1902 from Cornwall to the Cunard liner Philadelphia over a distance of 1,550 miles.

  Wireless worked better at sea than on land for a number of reasons. Marconi realised that, by using high electrical power—readily available in a large ship, with big engines and generators—at low frequency through very large aerials, he could take advantage of the “ground wave” which follows the curvature of the earth; reception was also facilitated by the reflection of waves between the earth’s surface and layers in the atmosphere. In the years after his great transatlantic transmission success, he also made other important discoveries, to do particularly with “tuning” transmission in to separate bands of the radio spectrum, which reduced interference, improved reception and allowed stations, whether at sea or on land, to be allotted different wave frequencies. He thereby met naval requirements, particularly British Admiralty requirements, which were for communicating simultaneously with large numbers of ships spread over a worldwide oceanic area.

  That also required the building of a worldwide chain of shore radio stations, for even the best of Marconi’s wireless sets as yet lacked the power to broadcast globally. Thitherto intercontinental communication had been secured by cables, of which by the end of the nineteenth century Britain owned over 60 per cent; because non-British cables often passed through stations worked by British operators, Britain’s dominance of the cable network was even more complete than company prospectuses revealed. Britain had been absolutely ruthless about establishing control of the cable kingdom from the start of the cable era. It had laid the first transatlantic cable in 1858, and though that had been a commercial undertaking, thereafter the government either laid cables itself or subsidised private companies to do so. By 1870 Britain was linked to India by a cable that ran through Lisbon (capital of Britain’s oldest and most reliable ally) to Gibraltar (British since 1713), Malta (British since 1800) and Alexandria (effectively British after 1882).

  As the British empire expanded, cables followed the flag, down both coasts of Africa, to Australia and New Zealand and across the Pacific, via such remote and tiny places as Fanning Island, 3,450 miles from its Canadian connection at Vancouver and at almost the exact centre of that ocean. The drive to create an “all-red” network (red was the colour by which British colonies were distinguished on the map) became a strategic obsession. To achieve the all-red effect, cables were relaid, or duplicated by sea, until no part of the empire could not be signalled along cables secure from foreign interference. No matter that 140,000 miles of cable, the greatest length by far, belonged to private companies relaying commercial messages. The government exercised the right to priority at any time by prefacing its own signals with “clear the line, clear the line.” Moreover, it took the
view that the network, private or official, was a national asset. As the French government observed in November 1900, “England owes her influence in the world perhaps more to her cable communications than to her navy. She controls the news and makes it serve her policy and commerce in a marvellous manner.”6 The City of London, in particular, was “the hub of the world’s telegraphic and telephone systems,” with the result that “most of the industrialised world financed its trade through sterling-denominated bills drawn on London”; not only the industrialised world but also the primary producers, including Egypt (cotton), Argentina (beef), Australia (wool) and Canada (wheat). All that was achieved with a remarkably small reserve of gold, the guarantee of paper transaction, only £24 million in the Bank of England, compared with £95 million of gold and silver in the Bank of France, £40 million in Germany and £142 million in the United States in 1891.7 Strategic signals may have had priority; but the government was well aware that the Royal Navy ultimately existed to guard the nation’s commerce.

  For most of the nineteenth century Britain’s vast and ever-expanding merchant fleet sailed the seas without thought of foreign interference: as late as 1880, the Royal Navy was equal in size to the next seven navies combined. In the last decade of the century, other navies, the French, the American, the German, the Russian, the Japanese, began to challenge in supremacy, either in particular seas or worldwide. After 1900, when Germany passed the Naval Law inaugurating the creation of a High Seas Fleet, the principal challenge was laid by the Kaiser’s navy. Until then it had possessed little better than a coast-defence force. After 1900 it began to lay down battleships which were to be a match for those of the Royal Navy; it had already started to build cruisers, ships designed to scout for the battleships but also to menace an enemy’s merchantmen. The architect of German naval expansion was Admiral von Tirpitz, whose mind was fixed on battleship building. His navalist philosophy has been characterised as “risk theory,” the posing of a threat to the Royal Navy by a battleship force which, though not big enough to defeat it in home waters, would limit its power by menacing it with the danger of crippling damage in a surprise engagement.