History · AQA 8145/1A

The League of Nations in the 1920s

Spec: AQA 8145/1A ⭐⭐⭐ ⏱ 50 min AQA · Edexcel · OCR Grade 9
  • Describe the structure of the League of Nations and the role of its main bodies
  • Explain the work of the League's agencies and their humanitarian successes
  • Analyse the successes and failures of the League in settling disputes in the 1920s
  • Evaluate the structural weaknesses of the League and their impact on its authority
  • Assess how far the League succeeded in maintaining peace in the 1920s

📜 Historical Context

The League of Nations was born from the catastrophe of the First World War — the conflict that killed over 17 million people and shattered Europe's old order. US President Woodrow Wilson, convinced that secret alliances and arms races had caused the war, proposed a permanent international organisation in his Fourteen Points (January 1918). The League was written into the Treaty of Versailles (1919) and came into existence in January 1920. It was humanity's first serious attempt at collective security — the idea that nations acting together could prevent any future aggressor from going to war. Yet from its birth the League was crippled by a devastating irony: the nation that created it, the USA, never joined.

Key Dates Timeline

📅 January 1920
League of Nations officially founded. First Assembly meets in Geneva, Switzerland. USA Senate had already voted to reject membership (Nov 1919).
📅 1920 — Vilna
Poland seizes Vilna from Lithuania. The League protests but takes no action. Lithuania appeals — the League fails its first major test.
📅 1921 — Upper Silesia
League divides the disputed industrial region between Germany and Poland following a plebiscite. Seen as a moderate success.
📅 1923 — Corfu Incident
Italy bombards and occupies Corfu after Italian officials are killed in Greece. The League is bypassed; the Conference of Ambassadors forces Greece to pay compensation to Italy.
📅 1925 — Locarno
The Locarno Pact confirms Germany's western borders. The "Spirit of Locarno" creates optimism about international cooperation.
📅 1926 — Germany Joins
Germany admitted to the League and given a permanent seat on the Council — a major diplomatic step towards rehabilitation.
📅 1928 — Kellogg-Briand
65 nations (including USA and Germany) sign the Kellogg-Briand Pact renouncing war. Symbolic but lacks any enforcement mechanism.

Chain of Events: From Armistice to League

Nov 1918
Armistice ends WWI
→
Jan 1919
Wilson's 14 Points
→
Jun 1919
Treaty of Versailles
→
Nov 1919
US Senate rejects
→
Jan 1920
League founded

🔑 Core Content

The Structure of the League

The League was built around four main bodies, each with distinct roles:

📖
The Assembly
Every member nation sent representatives to the Assembly, which met once a year in Geneva. Each nation — whether a great power or a tiny state — had one vote. The Assembly could recommend action but could not force it; crucially, all decisions required a unanimous vote. This meant any single nation could block collective action.
📖
The Council
The real decision-making body of the League. It had four permanent members (Britain, France, Italy, Japan) and between four and nine elected non-permanent members who served for three-year terms. The Council met more regularly to deal with crises. Again, unanimity was required — each permanent member held a veto. Without the USA, the Council was dominated by Britain and France, whose own interests often conflicted with impartial action.
📖
The Secretariat
The administrative backbone of the League. The Secretariat carried out the day-to-day work, prepared reports, and maintained records. It was headquartered in the Palais des Nations in Geneva. The Secretary-General led it; Sir Eric Drummond (UK) was the first, serving 1920–1933.
📖
The Permanent Court of International Justice (PCIJ)
Based in The Hague, Netherlands. Countries could bring legal disputes before the Court for binding judgements. It handled over 30 cases in the 1920s–1930s, though it had no power to enforce its rulings if nations refused to comply.
⚠️
Critical Structural Flaw: Unanimous Voting
The requirement for unanimous votes in both the Assembly and the Council was a fatal weakness. Even if 47 out of 48 nations agreed on action, one dissenter could block it. This made imposing sanctions or military action virtually impossible, especially when a great power was involved in a dispute.

The League's Agencies and Humanitarian Work

While the League struggled with political disputes, its specialist agencies achieved genuine humanitarian successes that are often overlooked.

💡
Exam Relevance: Agencies as Evidence of Success
Examiners reward candidates who can name specific agency achievements. The ILO and WHO successes are crucial counter-evidence when evaluating "how far" the League succeeded — even if it failed politically, it achieved real humanitarian good.
AgencyFull NameKey Achievements
ILO International Labour Organisation Campaigned to limit child labour; pushed for an 8-hour working day; set minimum safety standards in factories; tackled conditions for workers worldwide
WHO World Health Organisation Worked to defeat diseases such as leprosy, malaria, and typhus; vaccinated millions; published health data; foundations for modern WHO
Refugees Commission Nansen Refugee Agency Under Fridtjof Nansen, returned 400,000 WWI prisoners of war to their homes; created the "Nansen passport" for stateless refugees
Slavery Commission Temporary Slavery Commission Worked to suppress slavery and the slave trade; freed over 200,000 slaves in Sierra Leone; took action against forced labour
Mandates Commission Permanent Mandates Commission Supervised territories taken from Germany and Turkey after WWI, ensuring colonial powers governed them responsibly

Political Successes in the 1920s

✅
Aaland Islands (1921)
Both Sweden and Finland claimed the strategically placed Aaland Islands in the Baltic Sea. The League investigated and awarded them to Finland but insisted they remain demilitarised. Sweden accepted the verdict peacefully. This is considered the League's cleanest political success — both parties accepted the ruling.
✅
Upper Silesia (1921)
A plebiscite (referendum) in the industrially rich region produced a messy result: the population was split, with different areas voting for Germany or Poland. Riots broke out. The League stepped in, divided the territory along ethnic lines, and both sides — reluctantly — accepted the decision. Not a perfect solution, but it demonstrated the League could act.

Political Failures in the 1920s

❌
Vilna (1920) — The First Major Failure
Lithuania claimed Vilna as its capital. In October 1920 a Polish general, Lucjan Zeligowski, defied his own government (with its secret blessing) and seized the city. Lithuania appealed to the League. Despite this being a clear violation of sovereignty, the League did nothing effective. Britain and France were unwilling to confront Poland (a useful buffer state against Germany). Vilna remained Polish. This set a damaging precedent: the League would not act if it was inconvenient for major powers.
❌
Corfu Incident (1923) — Exposed by a Major Power
After five Italian boundary officials were killed on Greek soil while surveying the Greek-Albanian border, Mussolini's Italy bombarded and occupied the Greek island of Corfu (August 1923). Greece appealed to the League. The League condemned Italy and ordered it to withdraw — but Italy refused and instead brought the matter to the Conference of Ambassadors (a rival great power body). The Ambassadors forced Greece to apologise and pay compensation to Italy. Italy withdrew, but had effectively bullied the League. Key lesson: the League could not stand up to an aggressive great power.

Why the League Seemed to Work in the 1920s

Despite its failures, most contemporaries believed the League was broadly a success in the 1920s. Several factors explain this relatively positive perception:

🔍
Favourable Conditions in the 1920s
  • Disputes were between smaller nations — the League could use its moral authority without facing down great powers
  • Germany was excluded until 1926 — the main revisionist power was not yet challenging the settlement
  • The great powers were recovering — Britain and France were exhausted by WWI and unwilling to rock the boat
  • US economic prosperity — the Dawes Plan (1924) and American loans stabilised Europe financially, reducing tensions
  • The "Spirit of Locarno" (1925) — apparent goodwill between nations created optimism about peaceful change
  • Kellogg-Briand Pact (1928) — 65 nations renouncing war seemed to signal a new era

The Structural Weaknesses of the League

⚠️
No Permanent Army
The League had no military force of its own. It could ask member nations to contribute troops, but there was no obligation to do so. Britain and France were reluctant to commit armies to distant disputes. Without the threat of force, economic sanctions were the League's only real weapon — and these too depended on member cooperation.
⚠️
USA's Absence
This was the most crippling weakness. Without the world's largest economy, the League's economic sanctions were far less powerful — the USA could simply trade with any nation being sanctioned. Without the USA's military potential, aggressors had less to fear. Wilson's ironic failure: he designed the League but could not deliver his own country's membership. The US Senate rejected membership twice (1919, 1920), fearing "entangling alliances" that might drag the USA into European wars.
⚠️
Unanimous Voting and the Veto
Any permanent member of the Council could veto action. Even in the Assembly, all resolutions required unanimous agreement. This made decisive action almost impossible — a nation being sanctioned could simply veto the sanctions against itself.
⚠️
Limited Membership
At its peak, the League had 58 members, but major powers were missing. The USA never joined. Germany was excluded until 1926 (as punishment for WWI). Russia (USSR) was excluded as a communist state until 1934. Japan and Germany left in 1933, Italy in 1937. The League was never truly a world organisation.

Key Figures

PersonRoleSignificance
Woodrow Wilson US President 1913–1921 Creator of the League concept (14 Points, 1918). Awarded Nobel Peace Prize 1919. Suffered a stroke campaigning for US membership; died 1924 having seen the Senate reject his vision. The USA never joined — the League's greatest irony.
Lord Robert Cecil British delegate; co-founder Leading British architect of the League Covenant. Tireless advocate throughout the 1920s–1930s. Awarded Nobel Peace Prize 1937. Said the League's failure was not inevitable — it had the tools, but nations lacked the will.
Gilbert Murray League official; intellectual Oxford classicist and League of Nations Union leader. Argued strongly for the League's moral authority. Represented the idealist position that international law and public opinion could replace war.
Fridtjof Nansen High Commissioner for Refugees Norwegian explorer who ran the League's refugee and prisoner-of-war work. Created the "Nansen passport." Returned 450,000 prisoners home. Awarded Nobel Peace Prize 1922.

🔍 Analysis

Why the League Failed to Stop Aggression: Cause-Consequence Chain

USA absent
No economic/military power
→
Sanctions toothless
USA still trades
→
No army
Cannot enforce decisions
→
Aggressors not deterred
Corfu / Vilna
→
League's authority collapses
1930s crises follow

Four-Panel Revision Summary

Causes of Weakness
  • USA Senate refused membership (1919–1920)
  • No League army; no enforcement power
  • Unanimous voting = paralysis
  • Germany / USSR excluded initially
  • Britain and France prioritised self-interest
  • Economic sanctions required full cooperation
Consequences of Failure
  • Vilna: small nations learned League could not help
  • Corfu: great powers learned they could defy it
  • Emboldened aggression in 1930s (Manchuria, Abyssinia)
  • Undermined faith in collective security
  • Germany's revisionism went unchecked
Significance
  • First attempt at permanent collective security
  • Humanitarian agencies genuinely helped millions
  • Established precedent for UN (1945)
  • USA's absence a model of isolationism's dangers
  • Showed unanimous voting makes action impossible
Key Figures
WilsonCreator, never joined
CecilBritish champion
MurrayIdealist intellectual
NansenRefugee champion
MussoliniExposed limits (Corfu)

Grade 9 Debate: Structural Weakness vs Lack of Will

🏆
The Core Grade 9 Question

Was the League doomed by its structural weaknesses from the start, or did it fail because nations lacked the political will to use it?

Structuralists argue: the absence of the USA, the requirement for unanimity, and the lack of an army made failure inevitable regardless of political will. Even with perfect goodwill, one nation's veto could paralyse action.

Will-focused historians argue: the structures could have worked if Britain and France had truly committed to collective security. Lord Cecil himself argued that the League had sufficient tools — it was betrayed by the self-interest of its leading members. Corfu showed that when Britain and France chose to bypass the League, it was powerless; when they supported it (Aaland, Upper Silesia), it worked.

🧠
Mnemonic: League Weaknesses — "NAUM"
  • No army — could not enforce decisions
  • Absent USA — sanctions ineffective; no military deterrent
  • Unanimous voting — any nation could veto action
  • Membership limited — not truly global; USSR and Germany excluded
🧠
Mnemonic: League Successes in the 1920s — "AURS"
  • Aaland Islands (1921) — awarded to Finland; Sweden accepted
  • Upper Silesia (1921) — divided between Germany and Poland
  • Refugees — Nansen returned 450,000 prisoners; created Nansen passport
  • Slavery — freed 200,000 slaves; tackled forced labour in Sierra Leone

🔎 Source Analysis

💡
NOP Technique for Source Utility Questions

Nature — What type of source is it? (cartoon, speech, photograph, letter?)

Origin — Who created it, when, and where? What is their position/purpose?

Purpose — Why was it created? To persuade, to inform, to criticise? This affects reliability.

Always link back to the enquiry question: "useful for finding out about X because..."

Worked Example — Source A
Source A: A British newspaper cartoon published in September 1923, showing Mussolini standing triumphantly on a sinking Greek fishing boat labelled "Corfu", while a figure representing the League of Nations watches helplessly from the shore, its hands tied with rope.

How useful is Source A to a historian studying the League's response to the Corfu Incident?
1
What It Shows (Content)
The source shows Mussolini dominating the Corfu situation while the League is rendered powerless. The tied hands symbolise the League's inability to act against a great power. The cartoon suggests Britain viewed the League's failure to enforce its authority as a damaging humiliation.
2
Provenance
Published by a British newspaper in September 1923, shortly after the Corfu incident. The timing means the cartoonist had direct knowledge of events. A British newspaper would be concerned about British credibility — as co-guarantor of the League alongside France, Britain's failure to stand firm reflected poorly on British foreign policy as well as the League itself.
3
Inference
We can infer that contemporary British opinion saw the Corfu Incident as a clear failure of the League — that the League's authority was damaged when it could not prevent or punish an aggressive great power. The "tied hands" metaphor suggests structural weakness (lack of enforcement power) rather than unwillingness, though both interpretations are valid.
4
Utility Judgement
The source is useful as evidence of how contemporaries perceived the League's weakness after Corfu — particularly the view that the League was structurally unable to challenge great powers. However, it is limited in that: it reflects one nation's perspective (British); as a cartoon it exaggerates for satirical effect; and it cannot tell us whether the failure was structural or a lack of political will from Britain and France.
Strong sources answer: links content + provenance + NOP + specific knowledge + balanced limitation judgement.
Worked Example — Source B
Source B: An extract from a speech by Lord Robert Cecil to the League of Nations Assembly, Geneva, 1926: "The League has proved that it is possible for nations to work together in peace and common purpose. Our agencies have brought hope to millions of refugees and to workers who toil under dangerous conditions. We must not judge the League only by the difficult political disputes — judge it also by the children it has protected and the diseases it has conquered."

How useful is Source B to a historian studying the successes of the League of Nations in the 1920s?
1
What It Shows (Content)
Cecil argues the League should be judged on its humanitarian work — refugee relief and workers' protection — rather than political disputes. This directly supports the view that the League's agencies (ILO, WHO, Nansen's Refugee Commission) achieved real successes even when its political work failed.
2
Provenance
Cecil was the leading British champion of the League — he helped design the Covenant and spent his career defending it. Speaking at the Assembly in 1926 (the year Germany joined, a high point of optimism), he would naturally wish to emphasise achievements. His close involvement means he has direct knowledge, but also a strong personal and professional stake in making the League look successful.
3
Inference
We can infer that even League supporters in 1926 felt they needed to defend the organisation against criticism of its political failures — otherwise Cecil would not need to redirect attention to humanitarian work. This suggests contemporaries were already aware that the political record was mixed at best.
4
Utility Judgement
Useful for understanding what League supporters believed it had achieved and how they justified its value. Also useful as evidence of the real humanitarian successes of the ILO, WHO and refugee agencies. However, limited because: Cecil is a biased, committed advocate; the speech is deliberately persuasive and one-sided; it does not engage with the League's political failures (Vilna, Corfu). A historian would need to cross-reference with evidence of what the agencies actually achieved.
Remember: utility = what it IS useful for + what it is NOT useful for. Both sides earn marks.

❓ Exam Practice

Q1
4 marks

Give two things you can infer from Source A (the 1923 British cartoon of the Corfu Incident) about the League of Nations' ability to deal with aggression by a great power.

Inference 1: I can infer that the League was powerless to stop Mussolini's aggression against Corfu. Details in the source that tell me this: the figure representing the League has its hands tied, suggesting it was structurally unable to take action against Italy.

Inference 2: I can infer that Mussolini felt confident defying the League without consequences. Details in the source that tell me this: Mussolini is shown standing triumphantly — he is in a position of strength, not under pressure, suggesting the League had no real power to deter or punish him.

Mark scheme: 1 mark for each inference + 1 mark for supporting detail from source = 2 × 2 marks = 4 marks.

Q2
8 marks

How useful are Sources A and B to a historian studying the successes and failures of the League of Nations in the 1920s? Explain your answer, using Sources A and B and your own knowledge.

Level 4 answer (7–8 marks) would include:

  • Source A utility: Useful for showing how contemporaries perceived the League's failure at Corfu — the "tied hands" image captures the structural argument that the League could not enforce decisions against great powers. Limitation: British perspective only; cartoon exaggerates; cannot distinguish between structural weakness and lack of will.
  • Source B utility: Useful for demonstrating the real humanitarian achievements of the League's agencies — Cecil's detailed claims about refugees and workers are corroborated by historical knowledge of the ILO, WHO and Nansen's work. Limitation: Cecil is an advocate with a personal stake; speech is deliberately one-sided and promotional; does not address political failures.
  • Own knowledge integration: Source A corroborated by Corfu facts (Greece forced to pay compensation; League bypassed by Conference of Ambassadors). Source B corroborated by ILO reducing child labour, WHO vaccination campaigns, Nansen returning 450,000 prisoners.
  • Overall judgement: Together the sources are useful because they show both sides of the League's record — political weakness and humanitarian achievement — though both sources have significant limitations due to provenance and purpose.
Q3
8 marks

Write a narrative account analysing the events surrounding the Corfu Incident of 1923 and what it revealed about the League of Nations.

Level 4 answer (7–8 marks) — mark scheme key points:

Beginning: In August 1923, a team of Italian boundary officials, including General Tellini, were killed on Greek soil near the Albanian border. Mussolini blamed Greece and used the incident as a pretext for aggression.

Development 1 (cause-effect link): Mussolini issued an ultimatum demanding a large indemnity and a formal Greek apology. When Greece did not fully comply, Italy bombarded and occupied the Greek island of Corfu. The scale of the response was wildly disproportionate to the original incident, suggesting Mussolini was testing the new international order.

Development 2 (consequence with analysis): Greece appealed to the League, which condemned Italy's actions. However, Italy refused to accept the League's jurisdiction and instead brought the case to the Conference of Ambassadors — a rival body of great powers. Britain and France, unwilling to antagonise Mussolini (whom they saw as a valuable counterweight to communism), allowed the Ambassadors to override the League. Greece was forced to apologise and pay 50 million lire in compensation to Italy.

End (analytical conclusion): The Corfu Incident was deeply significant because it revealed that the League had no power when a great power was determined to defy it. It showed that Britain and France prioritised their own diplomatic interests over collective security, and that without their full support, the League was paralysed. The incident set a dangerous precedent for the 1930s, encouraging more aggressive powers to test the system.

Note: ensure the account has clear cause-effect links between paragraphs, not just a list of events.

Q4
16 marks

"The main reason the League of Nations failed to keep the peace in the 1920s was the absence of the United States." How far do you agree with this statement? Explain your answer.

Level 4 answer (13–16 marks) — essay plan:

Introduction: Define what "failed to keep the peace" means — note the League did have successes (Aaland, Upper Silesia) but also significant failures (Vilna, Corfu). The USA's absence was hugely damaging but was not the only reason for failure.

Paragraph 1 — AGREE (USA's absence was critical): The USA was the world's largest economy; without it, economic sanctions were toothless because America could still trade with sanctioned nations. The USA also had the military strength to deter aggressors. Wilson had designed the League specifically requiring US power. The Senate rejected membership in 1919–1920, fearing entanglement in European conflicts. This left the League dependent on Britain and France — neither fully committed nor economically/militarily dominant enough.

Paragraph 2 — Other structural weakness (no army, unanimity): Even with the USA present, the unanimous voting requirement could paralyse the Council. No permanent army meant enforcement was always uncertain. The veto meant any permanent member could block action against itself — illustrated when Italy brought the Corfu case to the Ambassadors rather than face League censure.

Paragraph 3 — Lack of will (Britain and France): Britain and France's self-interest arguably mattered more than USA's absence. At Corfu they chose not to support the League when it would have meant confronting Mussolini. At Vilna, Poland was too useful as a buffer against Germany to antagonise. Lord Cecil argued the League failed not because it lacked the tools but because its leading members lacked the will. This is a powerful counter-argument to the USA-centred view.

Paragraph 4 — Counter-evidence (League DID keep peace in some cases): The Aaland Islands and Upper Silesia show the League could work when great powers supported it. The humanitarian agencies show the League achieved real good. The 1920s saw no major European war — partly because conditions favoured peace, but the League contributed.

Conclusion: Agree that USA's absence was the single most damaging factor — it undermined sanctions, deterrence, and the moral authority of collective security. However, the failure was multi-causal: structural weaknesses (unanimity, no army) compounded the problem, and Britain and France's lack of will was equally significant. The League failed not solely because the USA was absent, but because the whole architecture of collective security depended on great power commitment that was never fully given.

Examiner tip: Level 4 requires a sustained analytical argument, not just agreeing or disagreeing. The best answers explain WHY USA absence mattered more (or less) than other factors using specific evidence.

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✅ I Can...

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  • Name and describe the four main bodies of the League (Assembly, Council, Secretariat, PCIJ)
  • Explain why the USA did not join the League and why this mattered
  • Describe the work of at least three League agencies (ILO, WHO, Nansen Refugees)
  • Explain the Aaland Islands dispute and why it is considered a success
  • Explain the Upper Silesia dispute and what it revealed about the League's methods
  • Analyse the Vilna dispute and what it revealed about the League's weaknesses
  • Analyse the Corfu Incident and explain why it was a significant failure
  • Explain all four structural weaknesses using the NAUM mnemonic
  • Explain why the League appeared to work in the 1920s despite its weaknesses
  • Evaluate the debate between structural weakness and lack of will in a 16-mark essay style
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