Although, as I argued in my blog of 5 March (see below), the German army’s offensives in the spring of 1918 were always likely to fail, they did enjoy some startling successes. The first few days of both Operation MICHAEL (which began on 21 March) and Operation GEORGETTE (9 April) strained the British army almost to breaking point. More British troops raised the white flag and went into captivity during the two weeks of MICHAEL than during the whole of the war on the Western Front up until then: 75,000, in all. This was less the result of a general loss of morale than a symptom of British defensive tactics being sometimes unable to withstand a German attack which was always extremely violent and sometimes deployed stormtroop tactics to great effect.

One reason commonly put forward, by historians such as Tim Travers and Martin Samuels, for the failure of the British defence was that the BEF was trying, but failing, to put into effect tactics of ‘elastic defence-in-depth’ which they had cribbed from the Germans. ‘Elastic defence-in-depth’ (EDID) is a system, echeloned back from a thinly held front line, whereby most of one’s strength was held back, out of enemy artillery range, in a series of zones up to ten miles deep, which would operate rather like the crumple zones on a car. When attacked, forward garrisons were to give ground until the enemy, channelled into natural killing zones and disordered by his advance, could be counter-attacked and defeated by reserves manoeuvring up from deep. There is no question that GHQ ordered the BEF to organise their defences along such lines. Nor is there any doubt implementation was patchy and inconsistent, and that, when the Germans struck, many of the new defences were not complete, especially in the sector of the overstretched British Fifth Army.

To some extent, the British failed for a lack of resources: the manpower and material required to develop successive defensive positions in zones deep into the rear simply did not exist. To some extent, however, it is also represented as a conceptual shortcoming: the British, it is argued, never truly understood the idea of EDID, because (implicitly) they were either too dumb to grasp how it was supposed to work, or never possessed the tactical flexibility required to make it do so.

There is, however, a hidden assumption in here: that EDID was the best way of resisting offensives in modern warfare. With hindsight, we know that to be true. But in 1918 it was much less clear. Considerable doctrinal debate was continuing within the German officer corps, where three views of the best way to organise a defence contended. First, there were still a few traditionalists who believed that the morale advantages of holding firmly on to the front line (‘crust defence’) outweighed the rigidity of such a scheme and its vulnerability to enemy artillery fire. Secondly, there were the adherents of EDID, as outlined above. And there was a third group who, when they talked of ‘defence-in-depth’, had in mind not an elastic scheme of manoeuvre but a series of tough fixed defences echeloned deep. During the Third Battle of Ypres (July-November 1917), all three had been tried at one stage or another. None proved successful all the time. EDID had proved unable to prevent the ‘bite-and-hold’ tactics General Plumer used in late September 1917, but the crust defence employed at the Battle of Broodseinde (4 October) was no better at stopping the British. Although Ludendorff ordered an immediate return to EDID, in the mud of the Passchendaele Ridge defences, although deep, became increasingly static. In any case weather, terrain and logistics robbed the British offensive of much more force than any German tactical genius.

In other words, the evidence of the last full-scale battle before spring 1918 was that there was no single defensive panacea on the Western Front (any more than a ‘silver bullet’ existed for the offence). If the Germans, who after all had several years of defensive experience on the Western Front, couldn’t make up their minds, why are we surprised that the British were caught in several minds? EDID was not some self-evident answer which the British were just too dumb to see.

Why, then, does the consensus think EDID was so obviously the solution? The answer begins, as it did in the case I discussed in my blog of 5 March, with the German official historians. To them, manoeuvrists to a man, EDID seemed the only possible way for an emasculated and outnumbered interwar Reichswehr to defend Germany against Poland or, heaven forbid, France.* Therefore, they played up EDID in their studies of the FWW, and so it entered the mainstream. The experience of the Wehrmacht during the Second World War, especially on the Eastern Front (and at least when Hitler wasn’t, ironically, insisting on ‘no retreat’), reinforced the apparent utility of EDID, and fed directly into US and NATO doctrine for the defence of Western Europe against the Warsaw Pact. So hindsight, and the agenda of the German official historians between the wars, have conspired to make the BEF look dumber than they probably would have done at the time.

* There is a final, intriguing possible hypothesis, which it would take much research to test, if it is possible at all to reconstruct what happened in sufficient detail. The final volume of Der Weltkrieg, Volume XIV, which deals with the events of 1918, was not finally compiled until probably about 1943 or even 1944, by which point Hitler had issued several ‘no retreat’ orders, in the face of opposition from his generals of the traditional Army. ‘No retreat’ has similarities with ‘crust defence’. Might the emphasis on EDID in the later volumes of the official history represent coded criticism of Hitler from the official historians? After all the Reichsarchiv was closely aligned with the old-school army and, indeed, had intimate ties with the plotters of July 1944….