Pearson Edexcel International GCSE in History · 4HI1 · Free · no account needed

The Schlieffen Plan and why it failed

Did the plan fail at Liège, at the Marne, or on the day it assumed Russia would need six weeks?

Option A1 · The origins and course of the First World War, 1905–18 › Key topic 3 · The Schlieffen Plan and deadlock on the Western Front — one of 3 lessons in this key topic. Paper 2 Section A — historical investigation: The origins and course of the First World War, 1905–18, key topic 3 (30 marks: 6 · 8 · 16).

Learn the Schlieffen Plan and why it failed, teach it to an AI pupil, then defend it in a marked debate — this lesson carries all three.

What the specification asks for

“The Schlieffen Plan and reasons for its failure” — examined through causation and consequence. Incandio is aligned to specification 4HI1; it is not published by, endorsed by or affiliated with Pearson.

1 · Understand it

The problem the plan was written to solve

After 1894 Germany faced war on two fronts against France and Russia simultaneously. Schlieffen's memorandum of 1905 proposed to solve it with time: defeat France in about six weeks, then move the army east by rail before Russia, with its vast distances and poor railways, could complete mobilisation.

The mechanism was a wheel through Belgium and the Netherlands to avoid the fortified Franco-German frontier, sweeping west of Paris and enveloping the French armies against their own eastern fortresses. The right wing was to be overwhelmingly strong — Schlieffen's supposed deathbed instruction was to keep the right wing strong — with the left in Alsace-Lorraine deliberately weak, inviting a French advance that would take French troops away from the decisive flank.

Two features are worth naming because they are the plan's real character. It was a schedule, with days assigned to the fall of particular towns. And it required the invasion of neutral states as a matter of routine, which meant that a German war with Russia would automatically become a war with France, Belgium and probably Britain — a political consequence produced by a military convenience.

Why it failed

Moltke's modifications. The younger Moltke, chief of staff from 1906, removed the Netherlands from the route to preserve a neutral trading window and strengthened the left wing in Alsace-Lorraine at the expense of the right. Whether this was decisive is argued: the strengthened left won a tactical victory at the frontiers which pushed the French back into precisely the positions from which they later counter-attacked.

Belgian resistance. Liège's forts held for around eleven days rather than the two assumed, and the Belgian army fell back on Antwerp instead of dissolving, requiring German forces to mask it. The delay was days rather than weeks and the destruction of Belgian railways compounded it.

Russian speed. Russia invaded East Prussia within about ten days, not the six weeks assumed. Moltke sent two army corps east on 25 August — they arrived after Tannenberg had already been won and were absent from the Marne.

Logistics and communication. The right wing marched around 500 kilometres in a month on foot; supply moved at the speed of horses while the schedule assumed the speed of the railways they had left behind. There was no radio a man could carry, so once armies were beyond telegraph lines, Moltke at headquarters in Luxembourg could not direct them.

The Marne. Kluck's First Army, at the end of the wheel, turned inside Paris rather than around it, exposing his flank. The French counter-attacked from Paris on 6 September, some troops famously moved by taxi, and a gap opened between the German First and Second Armies. A staff officer, Hentsch, was sent forward with authority to order a withdrawal and did so on 9 September. Germany retreated to the Aisne and dug in.

What the failure produced

The war Germany had planned to avoid: two fronts, no quick decision, and an economy that had not been prepared for a long conflict against a coalition with greater resources and command of the sea.

The Race to the Sea followed as each side tried to outflank the other northwards, until the line reached the Channel in November 1914 and there was no flank left. From then to March 1918 the Western Front moved very little.

There is a historiographical caution worth stating. The idea of a single fixed Schlieffen Plan rests heavily on a 1905 memorandum, and Terence Zuber has argued that it was a staff study rather than an operational plan and that the whole conception was constructed after the war to explain the defeat. Most historians reject the strong version of his case and it has changed how confidently the plan is described. For 4HI1 the specification names it, so it is taught, and a candidate who knows the argument exists has something genuinely useful for the interpretation question.

2 · Learn it — the notes

The dates that earn marks

1905
Schlieffen's memorandum. Why this date: The document the plan is reconstructed from, and the object of the historiographical dispute.
4–16 August 1914
Liège holds for about eleven days. Why this date: The first delay, and it is measured in days rather than the weeks often claimed.
17–20 August 1914
Russia invades East Prussia within about ten days of mobilising. Why this date: The assumption that fails hardest, and it produces the transfer of two corps west to east.
6–9 September 1914
First Battle of the Marne; Kluck turns inside Paris; Hentsch orders withdrawal. Why this date: The plan ends here, five weeks in, and the war of movement ends with it.

The figures, and how far to trust them

  • About 6 weeks — The time the plan allowed to defeat France.
  • About 11 days — Liège's resistance, against an assumed two.
  • About 500 kilometres — The distance the right wing marched in a month, on foot.
  • 2 army corps — Sent east on 25 August; they arrived after Tannenberg and were absent from the Marne.

The people to place

  • Alfred von Schlieffen — Chief of staff to 1906; author of the 1905 memorandum.
  • Helmuth von Moltke the Younger — Modified the plan and lost control of it; replaced after the Marne.
  • Alexander von Kluck — Commanded the First Army and turned inside Paris, exposing his flank.
  • Joseph Joffre — French commander who kept his nerve through the retreat and counter-attacked at the Marne.
  • Richard Hentsch — Staff officer sent forward with authority to order the withdrawal on 9 September.

How historians disagree

Attributed interpretations, never voiced — the AO4 seam.

  • The 'Moltke ruined it' reading: Schlieffen's plan would have worked and Moltke weakened the right wing, removed the Dutch route and sent two corps east at the decisive moment. Contested by The reading that the plan's assumptions were never achievable — 500 kilometres on foot, supply by horse, no portable radio, and a six-week Russian mobilisation that was already out of date by 1914 — so that no execution could have delivered it..

What students say — and what is actually the case

Not this: The plan failed because of brave Belgian resistance.

This: Liège cost around eleven days, which was serious and not decisive. Russia's speed, the logistics of a 500-kilometre march and the turn inside Paris did more, and a good answer ranks them rather than choosing the most flattering.

Not this: The plan was a fixed, detailed operational scheme.

This: It is reconstructed largely from a 1905 memorandum, and Zuber has argued it was a staff study. Most historians reject the strong form of his case, and the dispute is worth knowing because it is exactly the kind of thing the interpretation question is set on.

Two things students merge

Blurred: The plan and its execution.

The distinction: Whether the plan was flawed and whether it was badly executed are two questions. An answer that argues only one has taken a side in the historiographical dispute without noticing.

Blurred: Mobilisation and deployment.

The distinction: Russia mobilised slowly and deployed its first armies into East Prussia quickly. The plan's assumption was about the second and it was the second that failed, which is the precise version of the point.

What a Grade 9 answer holds here

A Grade 9 answer asks what the plan assumed rather than what went wrong with it. It assumed six weeks of Russian slowness, a two-day Liège, and armies marching 500 kilometres that could still be directed from Luxembourg — and once those are stated, the question of whether Moltke ruined it becomes a question about whether it was ever executable.

3 · How it is examined

This strand is genuinely set through: Paper 2 Section A (a) (6 marks — “Describe TWO features of EITHER … OR ….”); Paper 2 Section A (b) (8 marks — “How far does Source A support the evidence of Source B about …? Explain your answer.”); Paper 2 Section A (c) (16 marks — “Extract C suggests that …. How far do you agree with this interpretation? Use Extract C, Sources A and B and your own knowledge to explain your answer.”).

What earns marks: Ranking the causes with a stated criterion, and knowing that the plan's existence is itself contested. On p2a-c that turns a description of a failure into an evaluation of an interpretation.

4 · Prove it — the questions

Answered inside Incandio, where a marker checks what a correct answer must contain and tells you which half was missing. The marking stays in the app; the questions are here.

  1. Describe TWO features of the Schlieffen Plan. [6 marks · Paper 2 Section A (a)]
  2. How far does Source A support the evidence of Source B about the reasons for the failure of the Schlieffen Plan? Explain your answer. [8 marks · Paper 2 Section A (b)]
  3. Describe TWO features of the First Battle of the Marne. [6 marks · Paper 2 Section A (a)]
  4. Extract C suggests that the Schlieffen Plan failed because of Moltke's changes. How far do you agree with this interpretation? Use Extract C, Sources A and B and your own knowledge to explain your answer. [16 marks · Paper 2 Section A (c)]
  5. How far does Source A support the evidence of Source B about the German advance in August 1914? Explain your answer. [8 marks · Paper 2 Section A (b)]

Decide it

This lesson feeds a Decide History judgement — a position you commit to, an objection you answer, a criterion you name: Was there a moment in July 1914 when the war could still have been stopped?.

Think you understand it?

Reading is the start. On Incandio a topic counts as mastered only once you have taught it and defended it — the two things a revision guide cannot ask of you.

Incandio this topic → Prove it. Teach it. Defend it. What does “Incandio it” mean?

  1. Prove it — five questions on the Schlieffen Plan and why it failed, marked on the spot, that tell you what was missing rather than just what was wrong.
  2. Teach it — Explain the Schlieffen Plan and why it failed — what happened, why, and what it made possible — to Ember, an AI pupil who asks the awkward question. Understanding is credited; wording is not required.
  3. Defend it — Argue the Schlieffen Plan and why it failed against the historical mind with the strongest claim on it — three rounds, marked against descriptors you can read before you begin.
  4. Then the exam — 16 authored exam-style questions on this option, marked on Incandio with the mistake you actually made named.

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The debate is against The Charge That Moltke Ruined It — the case itself, argued at its strongest, because on this strand there is no single person whose position the learner has to defeat.

The same people, elsewhere in the option

Carry on through the option