Looking at photographs of the Third Battle of Ypres (31 July – 10 November 1917), it’s hard to imagine what possible justification there might have been to put men through such hell. How could this be anything but a futile mistake earned at a cost of a quarter of a million casualties? But do these shocking visions of men, animals, guns and tanks drowning in mud prevent us from assessing the achievements of this battle?
The preliminary attack at Messines was a great success
Prior to the main attack at Ypres, a preliminary offensive was launched in June at the Messines Ridge, a stronghold to the south. It was carried out by the British Second Army, under the command of General Herbert Plumer. Plumer planned the attack in meticulous detail.Nineteen mines were detonated before zero hour, producing the loudest man-made sound ever recorded at that time. The mines killed thousands of German soldiers and left others stunned and incapacitated. Nine divisions of infantry followed. The men were drawn from Australia, Canada, New Zealand, and Britain.
With support from artillery bombardments and tanks, the infantry secured the ridge without suffering the kinds of casualty rates normally associated with Western Front attacks.
German defence in depth was defeated by a change in tactics
In 1917, the German Army adopted a new defensive strategy called elastic defence, or defence in depth. Rather than a heavily defended front line, they created a series of defensive lines that worked together to grind down attacks. The real power of this defence came from the rear in the form of powerful counterattacking forces called eingriff.
The initial attacks at Ypres in July and August, planned by General Hubert Gough, fell foul of this new defence. Gough’s plan called for attacks to push deep into the German defence. Exactly the sort of move defence in depth was designed to exploit.
General Plumer took over command in the last week of August and changed Allied tactics. Plumer favoured a bite and hold approach, which successfully blunted the aggressive German defence. Attacking forces advanced on limited objectives within the range of their own artillery, dug in, and prepared to defend against the German counterattacks. The artillery moved forward and they repeated the process.
Allied infantry and artillery performed well
The infantry and artillery had come a long way since the Somme in the summer of 1916. In 1917 the British Army was increasingly adept at using artillery and infantry together, rather than viewing them as separate arms.
Even in the early unsuccessful attacks at Ypres, the Allies skilfully combined infantry attack with creeping and standing barrage. But Plumer’s bite and hold tactics really showcased this combined arms approach.
The successful use of combined arms and all arms warfare was an important contributing factor to Allied victory in the war.
Victory might have been decisive but for the weather
General Plumer’s bite and hold tactics produced a hat-trick of successful operations at the Menin Road, Polygon Wood, and Broodseinde. This triple blow crushed German morale, pushed casualties above 150,000 and left some commanders considering a withdrawal.
However, after a period of decent weather, conditions worsened in mid-October. Subsequent attacks proved less and less successful. Douglas Haig ordered the offensive to press on in order to capture the Passchendaele Ridge. This decision further bolstered post-war accusations against him.
The attrition rate was catastrophic for the German Army
By far the most significant result of Passchendaele was the catastrophic impact it had on the German Army. Eighty-eight divisions, half of its strength in France, were drawn into the battle. Despite their best efforts to develop new defensive tactics they suffered a devastating rate of casualties. They simply could not replace this manpower.
Erich Ludendorff, the German military commander, knew his forces could not afford to be drawn in to more attritional battles. Coupled with the knowledge that the US Army would soon arrive in Europe, Ludendorff opted to launch a series of massive offensives in the Spring 1918 – a last gasp attempt to win the war.