by John Keegan
What Rommel was achieving on his tiny but critical sector was being repeated elsewhere. The Germans and Austrians, penetrating the steep defile of the Isonzo valley, by-passing Italian strongpoints and striking for the high ground, were biting out an enormous gap in the Italian front, fifteen miles wide, leaving behind them four Italian divisions isolated and surrounded. Moreover, the deeper the Austro-German Fourteenth Army advanced, the more they threatened the flanks of the larger concentrations of Italian troops to north and south, menacing the whole of Cadorna’s eastern front with the collapse of its rear area. The rational alarm of the high command was reinforced by panic in the ranks. Rumour of enemy breakthrough undermined the will of the common soldiers to resist, just as it would twenty-three years later when Rommel’s tanks would romp unchecked through the demoralised French army behind the Meuse. Lieutenant Rommel began to take prisoners in increasing numbers, first a few dozen, then hundreds, eventually a whole regiment 1,500 strong who, after hesitating to surrender to a single officer waving a white handkerchief as a signal of what he wanted—Rommel, always the individualist, had gone forward alone—suddenly threw down their arms, rushed forward to raise him to their shoulders and burst into shouts of “Evviva Germania.”77
The capitulation of this regiment, the 1st of the Salerno Brigade, came on the third day of the Caporetto battle. By then the whole Italian front on the Isonzo had fallen into collapse, the army was no longer obeying orders or even making a show of attempting to do so and hundreds of thousands of soldiers were streaming down from the mountains to the plains. There was worse; “reserves moving up prepared to do their duty were greeted with yells of ‘Blacklegs.’ [Austrian] troops encountered Italian units in formed bodies marching into captivity, calling out ‘Eviva la Austria.’ ”78 On 26 October Cadorna, a man beset by nightmare, realised that a general retreat to the Tagliamento, the next large river west of the Isonzo, was inevitable. The enemy, rampaging forward, did not allow him to rest there. Though the Italians blew the bridges behind them, their pursuers got across and by 3 November had pressed them back to the River Piave, a major obstacle not to be crossed except by a deliberate assault of which the exultant victors, who had outrun their lines of supply, were not capable. Nevertheless, their achievement had been extraordinary. In eleven days they had advanced eighty miles, to within striking distance of Venice, forced the retreat of the Italians from the whole length of their mountain frontier between the Tirol and its hinge on the sea, and captured 275,000 prisoners; Italian battle casualties amounted to the comparatively small total, by First World War standards, of 10,000 dead.
Cadorna did his best to increase the number, by a ruthless and characteristic institution of the summary execution of stragglers, an episode unforgettably described by Ernest Hemingway, an ambulance volunteer with the Italians, in A Farewell to Arms; he was not actually present but that does not detract from the veracity of his account, one of the greatest literary evocations of military disaster. Cadorna’s judicial savagery could not halt the rout nor did it save his neck. He had never trusted his fellow-countrymen; they, in return, had never found it in their hearts to like him or even to respect him, unless out of fear. When, in the aftermath of Caporetto, he attempted to cast responsibility for the army’s collapse on to defeatism in the rear—there had been an outbreak of strikes in August and sporadic effusions of enthusiasm for “Lenin” and “revolution”—he lost the government’s support. On 3 November, echoing sentiments expressed in France after the Nivelle offensive, he referred to the Caporetto retreat as “a kind of military strike.” Five days later he had been removed from command, to be replaced by General Armando Diaz who, like Pétain after the Nivelle catastrophe, would offer the common soldier a more indulgent regime of leave and comforts as an inducement to sustain the fight.79
In practice, the Italian army, like the French, would not resume the offensive until the following year. When it did so, it would be in the company of a far stronger foreign contingent, largely British, than any offered as a buttress to the French in 1918. Caporetto, one of the few clear-cut victories of the First World War, was a triumph for the Germans, a vindication of the military qualities of their faltering Austrian allies, and a major defeat for the Allies at the end of a year which had brought disabling setbacks to their cause. If it had one positive effect, it was to force Britain and France to recognise that their haphazard system of directing their war effort, through informal liaison and intermittently convened conferences, could not continue if the war was to be brought to a conclusion in their favour. On 5 November, an inter-Allied meeting was convened at the Italian city of Rapallo, at which it was decided to establish a permanent Supreme War Council, with responsibility to co-ordinate the Allies’ strategy, to sit at Versailles under the aegis of the British, French and Italian prime ministers and the President of the United States.
AMERICA, SUBMARINES AND PASSCHENDAELE
President Woodrow Wilson had said America was “too proud to fight,” a sentiment that mirrored his own distaste for war. High-minded, idealistic, academic, he had formed the belief that plain dealing between nations in open diplomacy was the secret of averting and evading conflict. During 1916 he had, through his emissary, Colonel Edward House, made a determined effort to bring the combatants to negotiation on terms he regarded as fair to all and he had been dispirited by its failure. He was not, however, unrealistic about the place of force in international affairs nor was he unwilling to use force if necessary. In 1915 he had brought Germany’s campaign of “unrestricted” submarine warfare to a close by a threat to use American naval power to preserve the freedom of the seas and he authorised Colonel House to promise to the Allies an American military intervention if they would accept his conditions for a peace conference and the Germans would not. As late as the spring of 1917, nevertheless, he had no intention of bringing his country to join the war, nor was there enthusiasm for entry among his fellow citizens. Among the large proportion of German descent were activists who, through the German-American Bund, campaigned against it.
Two events changed America’s outlook. The first was a clumsy German approach to Mexico, proposing an alliance, baited with the offer to return Texas, Arizona and New Mexico, if America went to war against Germany; this “Zimmermann telegram” was transmitted to the American government by British naval intelligence—though the U.S. State Department had intercepted it independently—and caused outrage when it was published on 1 March 1917. The second was Germany’s decision to resume the unrestricted U-boat campaign: sinking merchant shipping without warning in international waters.80 A return to the policy of 1915 had been debated in Germany since August 1916. The breach of maritime law, and its possible repercussions, was recognised. The prevailing code required commerce raiders, whether surface or submarine, to stop merchant ships, allow the crew to take to the boats, provide them with food and water and assist their passage to the nearest landfall before destroying their vessel. The unrestricted policy allowed U-boat captains to sink by gunfire or torpedo at will. The proponent of the policy was Admiral Henning von Holtzendorff, chief of the German naval staff, whose argument was that only through an all-out attack on British maritime supply could the war be brought to a favourable conclusion before blockade by sea and attrition on land had exhausted Germany’s capacity to continue the war. He demonstrated by statistical calculation that a rate of sinking of 600,000 tons of Allied, but largely British, shipping a month would, within five months, bring Britain to the brink of starvation, meanwhile also depriving France and Italy of the supply of British coal essential to the working of their economies. A similar argument was to be used by the German navy during the Second World War, when it instituted an unrestricted sinking policy from the start. In the spring of 1917, the German navy, with about a hundred submarines available for operations in the North Sea, Atlantic, Baltic and Mediterranean, was ordered to open unrestricted attack against the twenty million tons of British shipping, out of a total of thirty million world
wide, on which the British homeland depended for survival.81
Hindenburg and Ludendorff, though opposed by the Chancellor, Bethmann Hollweg, responded enthusiastically to Holtzendorff’s memorandum of 22 December 1916, urging the institution of unrestricted sinkings, and it was decided to take the risk—“fear of a break” (with the United States), Holtzendorff had argued, “must not hinder us from using this weapon that promises success”—at an imperial conference on 9 January 1917.82 The campaign, in the seas around the British Isles, on the west coast of France and in the Mediterranean, began on 1 February. The political effect in the United States was felt immediately and the severity of American reaction vastly exceeded German expectation. On 26 February, President Wilson asked Congress for permission to arm American merchant ships, the same day that two American women were drowned in the sinking of the Cunard liner Laconia by a German submarine. On 15 March German submarines made direct attacks on American merchant ships, sinking three. That was a direct challenge to the dignity of the United States as a sovereign power, one which Wilson reluctantly decided he could not ignore. On 2 April, before a special session of Congress, he reviewed the development of the German submarine campaign, declared it to be a “war against all nations” and asked Congress “to accept the status of a belligerent which has thus been thrust upon it.” Four days later Congress resolved that war against Germany should be formally declared. Declarations against Austria-Hungary, Turkey and Bulgaria followed, selective military conscription was enacted (18 May 1917) and the armed forces of the United States began at once to prepare for operations in Europe.
The mobilisation of the United States Navy, with the second largest fleet of modern battleships in the world after Britain’s, immediately altered the balance of naval power in the Atlantic and North Sea unchallengeably in the Allies’ favour; after December 1917, when five American Dreadnoughts joined the Grand Fleet, the High Seas Fleet, outnumbered by thirty-five to fifteen, could not hope to stand against it in battle.83 The United States Army, by contrast, was in April 1917 only 108,000 strong and in no condition to take the field; the federalisation of the National Guard, of 130,000 part-time soldiers, scarcely added to its effectiveness. The best American units belonged to the Marine Corps, but numbered only 15,000. Nevertheless, it was decided to form an expeditionary force of one division and two Marine brigades and send it to France immediately. Meanwhile, conscription would produce a first contingent of a million recruits, with another million to follow. It was expected that two million men would arrive in France during 1918.
The spectre of America’s gathering millions lent even greater urgency to Germany’s attempt to starve out its European enemies by U-boat action. The first months of unrestricted sinkings suggested that it might succeed. During 1915 the U-boats had sunk 227 British ships (855,721 gross tons), the majority in the first unrestricted campaign. During the first half of 1916 they sank 610,000 tons of shipping of all flags, but sinkings then declined sharply when, after May 1916, the German Admiralty reverted to stricter observance of maritime law. By the beginning of 1917, when an accelerated building programme had raised the total of U-boats to 148, sinkings rose proportionately, to 195 ships (328,391 tons).84 From February, when unrestricted sinkings began, the totals rose month by month to terrifying levels: 520,412 tons in February, 564,497 tons in March and 860,334 tons in April. Holtzendorff’s target of the 600,000 tons of monthly sinkings necessary to win the war had been exceeded, threatened to increase and bring Allied defeat.
The Admiralty could see no means to avert disaster. Arming merchant ships was pointless when U-boats attacked submerged with torpedoes. Mining the exits from the U-boat bases was ineffective, since British mines were unreliable and the bases too many and too inaccessible to be stopped up. Hunting U-boats, though tried, was like looking for a needle in a haystack, even on the shipping routes. Trapping U-boats with apparently harmless decoys not worth a torpedo, the celebrated “Q” ships disguised as small merchantmen but heavily armed, worked on odd occasions until the German captains got canny. Diversion of shipping away from identified danger areas reduced losses only until the U-boats tried elsewhere. Meanwhile the haemorrhage continued apparently unquenchably. U-boat losses were negligible: ten in October to December 1916, only nine in February to April 1917, two of which were to German mines. The Allies’ only anti-submarine weapon, the depth charge, was useless unless U-boats could be found, and the hydrophone, the only detection device, could not find U-boats beyond a few hundred yards.
There was a solution available—convoy—but the Admiralty resisted it. Sailing ships in groups, even under escort, seemed merely to offer a larger group of targets. As the Admiralty’s Operational Division wrote in January 1917: “it is evident that the larger the number of ships forming the convoy, the greater is the chance of a submarine being able to attack successfully.” The paper concluded by arguing that sailing “independently” was the safer procedure.85 The analysis was, of course, wrong. In the spaces of the sea, a group of ships is little more conspicuous than a single ship, and, if not found by a U-boat, all would escape attack. Single ships sailing in succession, by contrast, presented the U-boat with a higher chance of making a sighting and so a sinking. Moreover, the Admiralty had been deluded by another mathematical misperception. In attempting to estimate the number of escorts it would have to find if it adopted convoy, it counted all sailings, which amounted to 2,500 weekly from British ports, and concluded it had insufficient warships. It was only under closer analysis by the new Minister for Shipping, Norman Leslie, and a junior naval officer, Commander R. G. A. Henderson, that a more manageable picture was revealed. The number of weekly arrivals of ocean-going merchant ships, those that actually sustained the war, was only 120 to 140 a week, and for those sufficient escorts could easily be found.86
By 27 April the senior admirals were convinced of the need to adopt convoying—apparently not at Lloyd George’s prompting, as is usually stated—and on 28 April the first convoy was sailed. It reached Britain without loss on 10 May. Thenceforward convoy was progressively introduced for all oceanic sailings and losses began to decline. Even in August they were still running at 511,730 tons, and they stood at 399,110 as late as December. Not until the second quarter of 1918 would they drop below 300,000 tons monthly, by which time nearly four million of the world’s thirty million tons of shipping would have been sunk in a little over a year. It was convoy that had reversed the fatal trend; but, as in the second U-boat war of 1939–43, it was not any one measure that brought about the U-boat’s defeat. Important subsidiary measures included the systematic laying of mine barriers (70,000 in the Northern Barrier between Scotland and Norway), the dedication of large numbers of aircraft and airships to anti-submarine patrols in narrow waters (685 aircraft, 103 airships) and the multiplication of escorts (195 in April 1918).87
An important indirect effect of convoy was to draw the U-boats into coastal waters, to hunt unescorted small vessels, where air patrol, hydrophone and depth charge could more easily find them, and minefields claim victims. Of the 178 U-boats lost during the war, out of 390 built, 41 were mined, only 30 depth-charged. Direct attack on U-boat bases, as on the famous Zeebrugge raid of 23 April 1918, interrupted submarine operations not at all. Nevertheless, however uncertain and halting the anti-submarine campaign, Holtzendorff’s war-winning total of sinkings was never achieved. If the British did not exactly win the U-boat war, the Germans still managed to lose it.
The unrestricted campaign nevertheless had the effect of driving Britain to undertake what would become its most notorious land campaign of the war, the Third Battle of Ypres, or Passchendaele, so called after the village, destroyed in the course of the offensive, which became its ultimate objective. At the First Battle of Ypres in October–November 1914, the old BEF had succeeded in closing the gap between the open wing of the French army and the Flemish coast, so completing the Western Front. In the Second, in April 1915, the BEF had sustained the first gas attack of the
war in the Western Front and, though surrendering critical ground in front of the city of Ypres, had held the line. In 1917, the military situation in the British army’s sector was a novel one. The Germans, despite their success against the French and the Romanians, and despite the progressive enfeeblement of the Russian army, were no longer in a position, as they had been in the year of Verdun, to undertake offensive operations. Their armies were overstretched and Hindenburg and Ludendorff awaited a strategic shift of balance, perhaps to be brought by a U-boat victory, perhaps by a final Russian collapse, before they could realign their forces for a new and decisive effort. In the meantime the British, on whom Nivelle’s aborted campaign had cast the burden of carrying on the war in the west, considered their position.
