The Schlieffen Plan and the Race to Stalemate

Germany's greatest fear in 1914 was fighting France in the west and Russia in the east at the same time. Split between two fronts, its army could be overwhelmed.

The solution had been worked out years earlier by Count Alfred von Schlieffen, the head of the German army, and adjusted by his successor Moltke. Its logic rested on one key assumption: Russia was huge and disorganised, so it would take about six weeks to mobilise its vast army.

That gave Germany a narrow window. If it could knock France out fast, in those six weeks, it could then move its whole army east by railway to face Russia — fighting one enemy at a time instead of two at once.

The whole plan was a race against the clock. Everything depended on defeating France before Russia was ready. That single assumption is the key to understanding both why the plan was made and why it failed.

The plan avoided a direct attack on France's strong border defences. Instead, the German army would swing north through neutral Belgium, like a giant scythe, sweeping down into France, encircling Paris and trapping the French army.

The intended steps:

1. Send the bulk of the army through Belgium into northern France.
2. Sweep around west of Paris to encircle the French army from behind.
3. Force France to surrender within about six weeks.
4. Move the army east by rail to fight Russia before it was fully mobilised.

The great weakness was built in from the start: the plan required invading Belgium, a neutral country whose neutrality Britain had promised to defend. Attacking France therefore risked bringing in Britain — which is exactly what happened on 4 August 1914.

The plan unravelled in the opening weeks of the war. Several factors combined:

Factor	Effect on the plan
Belgian resistance	Belgium fought back harder than expected, slowing the advance and costing precious time
The British Expeditionary Force (BEF)	Britain's small but professional army delayed the Germans, notably at Mons (August 1914)
Faster Russian mobilisation	Russia mobilised in around 10 days, not six weeks, forcing Germany to react in the east early
Troops diverted east	Moltke moved soldiers from the western advance to the Eastern Front, weakening the crucial sweep
Moltke's changes	The plan was altered so the army passed east of Paris, not around it, exposing its flank
Exhaustion and supply	German soldiers were tired and outrunning their supplies after a rapid advance

The result was that the German army, instead of encircling Paris, marched into a trap of its own. By early September 1914 it was strung out, exhausted, and exposed near the River Marne.

The German advance was finally halted at the First Battle of the Marne (5–12 September 1914), fought east of Paris. French and British forces counter-attacked into a gap that had opened between the German armies.

The consequences were decisive:

• The German advance was stopped and pushed back to the River Aisne.
• Paris was saved and France was not knocked out of the war.
• The Schlieffen Plan had failed — Germany now faced exactly the two-front war it had feared.
• The quick war everyone had expected was over; a long war was now certain.

The Marne is one of the most important battles of the whole war, even though it is less famous than Verdun or the Somme. It is where Germany's plan for a short war died. When a question asks why the fighting lasted so long, the failure at the Marne is where the answer begins.

After the Marne, neither side could break through the other's line, so each tried to get around it. Both armies repeatedly marched north, each trying to outflank the other's western edge. This became known as the Race to the Sea (roughly September–November 1914).

Neither side won the race. As they advanced they dug trenches to hold the ground they had, and the lines simply extended northwards until they reached the English Channel. There was no open flank left to turn.

The First Battle of Ypres (October–November 1914) was among the last attempts to break through before winter. When it ended, a continuous line of opposing trenches stretched across the whole of the Western Front, and the war of movement was over.

By the end of 1914 the Western Front had frozen into stalemate: a continuous line of trenches running roughly 700 kilometres from the Swiss border to the North Sea, with no open ends to go around.

Why could neither side break through?

• Defensive weapons were far stronger than attacking ones. Machine guns, barbed wire and artillery made attacking across open ground almost suicidal.
• There were no flanks to outflank. The line was continuous, so the only way forward was a costly frontal assault.
• Reserves could be rushed by rail to plug any gap before an attacker could exploit it.

This is the heart of the war's tragedy: the technology of defence had outpaced the technology of attack. Understanding why stalemate set in is essential for the 16-mark essay on why the fighting lasted so long — the failed Schlieffen Plan started the deadlock, but it was these defensive conditions that kept it going until 1918.

The battles fought to try to break this deadlock — Verdun, the Somme and Passchendaele — belong to the war of attrition on the Western Front, covered in the next lessons.

1. Saying the plan failed only "because of Belgium"

Belgium slowed the advance, but the plan failed for several reasons together: faster Russian mobilisation, the BEF, Moltke's changes, exhaustion, and the halt at the Marne. Give a range of factors.

2. Not explaining how the failure caused the long war

Examiners note that many students say the plan failed but never link this to why the fighting lasted so long. The failure led to a two-front war and, at the Marne, to the stalemate — say so explicitly.

3. Confusing the reasons stalemate started with why it continued

The failed Schlieffen Plan and the Race to the Sea started the stalemate. It continued because defensive weapons beat attacking ones. Strong essays separate the two.

4. Forgetting the Battle of the Marne

The Marne is the turning point where the plan died and the trenches began. Leaving it out removes the pivot of the whole story.

5. Vague dates and distances

Use precise anchors: the plan aimed to beat France in about six weeks; the Marne was September 1914; the trench line ran from Switzerland to the sea. Precision moves an answer up the levels.