What you'll learn
This revision guide covers the League of Nations from its establishment in 1919 to its effective collapse by 1939. You'll examine the League's organisation, its early successes in the 1920s, and its catastrophic failures in the 1930s when faced with aggressive dictatorships. Understanding why the League failed is essential for explaining the origins of the Second World War.
Key terms and definitions
Collective security — The principle that all member nations would act together to stop aggression by any country, making war too costly for potential aggressors.
Mandate — A territory taken from Germany or Turkey after the First World War and placed under League supervision, administered by a major power on behalf of the League.
Sanctions — Economic or military penalties imposed by the League against an aggressor nation to force compliance with international law.
Disarmament — The reduction of military forces and weapons, a key League objective to prevent future wars.
Veto — The power of permanent Council members to block League decisions, requiring unanimous agreement for action.
Arbitration — The settlement of disputes between nations through negotiation and compromise rather than war.
Abyssinia — Independent African nation (modern Ethiopia) invaded by Italy in 1935, representing the League's greatest failure.
Appeasement — The policy of making concessions to aggressive powers to avoid conflict, which undermined the League in the 1930s.
Core concepts
The aims and organisation of the League
The League of Nations was established by the Treaty of Versailles in 1919, though the idea originated with US President Woodrow Wilson as part of his Fourteen Points. The organisation began work in January 1920 with headquarters in Geneva, Switzerland.
Primary aims:
- Maintain world peace through collective security
- Settle international disputes through negotiation and arbitration
- Improve living and working conditions globally
- Enforce the Treaty of Versailles
Main organs:
The Assembly met annually and included all member nations, each with one vote. It controlled the budget, admitted new members, and made major decisions. However, all decisions required unanimous agreement, which made swift action nearly impossible.
The Council met more frequently (initially four times yearly, later more often during crises) and included permanent members (Britain, France, Italy, Japan) plus temporary members elected by the Assembly. The Council was responsible for settling disputes and could recommend sanctions. Like the Assembly, it required unanimous decisions.
The Secretariat was the League's civil service, keeping records, preparing reports, and handling administrative work. It remained politically neutral.
Specialist agencies and commissions:
- The International Labour Organisation worked to improve working conditions
- The Mandates Commission supervised former German and Turkish territories
- The Refugees Committee helped displaced persons after conflicts
- The Health Organisation combated diseases and epidemics
- The Slavery Commission worked to abolish slavery worldwide
Critical weaknesses from the start
Despite noble aims, the League suffered fundamental flaws that ultimately guaranteed its failure.
Absence of key nations:
The USA never joined despite Wilson's role in creating the League. The US Senate rejected membership in 1919-20, fearing entanglement in European affairs and obligations under collective security. This removed the world's strongest economic power and undermined the League's authority and ability to enforce sanctions.
Germany was excluded until 1926 as punishment for causing the First World War. The USSR was excluded until 1934 due to communist ideology and Western distrust. Japan left in 1933 after being condemned for invading Manchuria. Italy left in 1937 following condemnation over Abyssinia. Germany left in 1933 when Hitler withdrew.
Structural problems:
The requirement for unanimous decisions meant any single member could block action. This paralysed the League when swift responses were needed. The League possessed no permanent army of its own and relied on members to contribute forces, which they were reluctant to do.
Britain and France dominated the League but had conflicting priorities. Britain focused on protecting its empire and avoiding European commitments. France sought security against German revival and wanted a strong League to enforce Versailles. Neither wanted to risk war to defend distant territories.
Limited powers:
The League could impose moral condemnation, economic sanctions, or recommend military force. However, economic sanctions required time to work and depended on all members participating. Military force required member contributions that rarely materialised. Aggressive nations simply ignored moral condemnation.
Successes in the 1920s
The League achieved notable successes in its early years when dealing with smaller nations and non-military matters.
Territorial disputes resolved:
- Åland Islands (1921): Dispute between Finland and Sweden over these strategic islands. The League awarded them to Finland but guaranteed Swedish residents' rights, satisfying both parties.
- Upper Silesia (1921): Industrial region claimed by both Germany and Poland. After a plebiscite produced unclear results, the League divided the territory, giving Poland the majority of industrial areas while protecting minorities on both sides.
- Corfu (1923): Italian general murdered on Greek-Albanian border. Mussolini bombarded and occupied Corfu. The League condemned Italy, but the Conference of Ambassadors (not the League) forced Greece to pay compensation. Italy withdrew. This showed the League's weakness when dealing with a major power.
- Bulgaria-Greece (1925): Greek troops invaded Bulgaria after border incidents. The League condemned Greece, which accepted the verdict and withdrew. Greece paid compensation. This success occurred because both nations were small and willing to cooperate.
Humanitarian work:
The League repatriated 400,000 prisoners of war after the First World War. The Refugees Committee helped resettle refugees from conflicts in Turkey and Russia. The Health Organisation coordinated campaigns against leprosy, malaria, and plague, establishing international standards for disease control.
The Slavery Commission freed 200,000 slaves in Sierra Leone and worked to end forced labour in Africa. The International Labour Organisation banned poisonous white lead from paint and limited working hours, improving conditions in member nations.
Failures in the 1920s and early warning signs
Even during the supposedly successful 1920s, the League demonstrated critical weaknesses.
Vilna (1920): Poland seized the Lithuanian capital of Vilna. Lithuania appealed to the League, but Poland refused to leave. Britain and France would not support military action. The League simply accepted the situation, demonstrating impotence against a determined medium-sized power.
The Corfu Incident (1923) showed that a major power could defy the League and achieve its objectives through aggression. Although Italy withdrew, it received compensation, rewarding its use of force.
The Disarmament Conference (1932-1934) aimed to reduce international tension by cutting weapons. Germany demanded equality with other powers. France refused unless guaranteed security. Hitler withdrew Germany from both the Conference and the League in 1933, ending hopes for disarmament. The failure revealed the League could not solve the fundamental security dilemmas between nations.
Manchuria 1931-1933: The turning point
The Manchurian Crisis marked the beginning of the League's catastrophic decline. In September 1931, Japan invaded Manchuria, a Chinese province rich in coal, iron, and resources that Japan needed for its growing industry and population.
Japan claimed it acted to protect Japanese citizens after the Mukden Incident (an explosion on the Japanese-controlled railway, probably staged by Japan itself). Despite Chinese appeals to the League, Japanese forces completed the conquest by early 1932, establishing the puppet state of Manchukuo.
The League's response:
Lord Lytton led a commission that investigated for months before reporting in October 1932. The Lytton Report condemned Japan and ordered withdrawal from Manchuria. Japan simply ignored this, left the League in March 1933, and kept Manchuria.
Why the League failed in Manchuria:
- Britain and France were distracted by the Great Depression and unwilling to commit resources to distant Asia
- The USA was not a member and would not support sanctions
- The League had no army to force Japanese withdrawal
- Economic sanctions were not imposed because they might push Japan toward war
- The slow response (taking over a year) allowed Japan to consolidate control
Significance:
This failure demonstrated that the League could not stop a determined major power. It encouraged other potential aggressors, particularly Italy and Germany, who observed that aggression succeeded without serious consequences.
Abyssinia 1935-1936: The League's death blow
The Abyssinian Crisis destroyed the League's remaining credibility. In October 1935, Fascist Italy under Mussolini invaded Abyssinia (Ethiopia), one of only two independent African nations and a League member.
Mussolini sought an empire to match Britain and France, to avenge Italy's humiliating defeat at Adowa in 1896, and to distract Italians from economic problems. He used a border clash at Wal-Wal as a pretext for invasion.
The League's response:
Emperor Haile Selassie appealed to the League, which condemned Italy as an aggressor and imposed economic sanctions in November 1935. However, these sanctions excluded oil (the most vital material for Italy's war effort) because Britain and France feared pushing Mussolini into alliance with Hitler.
The Hoare-Laval Pact (December 1935) represented the ultimate betrayal. British Foreign Secretary Samuel Hoare and French Premier Pierre Laval secretly agreed to give Mussolini two-thirds of Abyssinia if he stopped fighting. When the plan leaked, public outrage forced both men to resign, but the damage was done.
Italy completed its conquest by May 1936 using aircraft, poison gas, and modern weapons against poorly-armed Ethiopian forces. The League lifted sanctions in July 1936, tacitly accepting Italian victory.
Why the League failed in Abyssinia:
- Britain and France prioritised maintaining Italy as an ally against Hitler over defending League principles
- The Suez Canal remained open to Italian troop ships, undermining sanctions
- Oil sanctions were never imposed, allowing Italy to continue military operations
- No member nation would risk war to defend Abyssinia
- The Hoare-Laval Pact revealed Anglo-French hypocrisy and willingness to abandon collective security
Consequences:
This failure destroyed the League's authority completely. It proved collective security was meaningless. Mussolini allied with Hitler, forming the Rome-Berlin Axis in 1936. Small nations abandoned faith in the League. Hitler observed that aggression worked and Britain and France would not fight to maintain the peace settlement, encouraging his expansionist policies.
The League's collapse 1936-1939
After Abyssinia, the League became irrelevant as European tensions escalated toward world war.
Key events demonstrating the League's irrelevance:
Remilitarisation of the Rhineland (March 1936): Hitler violated the Treaty of Versailles by sending troops into the demilitarised Rhineland. The League took no action. France would not act without British support. Britain considered the Rhineland "Germany's own back garden."
Spanish Civil War (1936-1939): The League played no role as Italy and Germany supported Franco's fascists while the USSR supported Republicans. Britain and France pursued non-intervention, abandoning Spain to its fate.
Anschluss with Austria (March 1938): Hitler annexed Austria in clear violation of Versailles. The League did nothing. Britain and France accepted the fait accompli.
Munich Crisis (September 1938): Hitler demanded the Sudetenland from Czechoslovakia. Britain and France negotiated directly with Hitler at Munich, completely bypassing the League and sacrificing Czechoslovakia through appeasement.
Invasion of Czechoslovakia (March 1939): Hitler seized the remainder of Czechoslovakia. The League was not even consulted.
The League formally continued to exist and met occasionally, but member nations resolved crises through bilateral diplomacy or simply accepted aggression. When the Second World War began in September 1939, the League was powerless to prevent or respond to it. The organisation officially dissolved in 1946, replaced by the United Nations.
Worked examples
Example 1: Describe the key features of the organisation of the League of Nations. [4 marks]
Model answer:
The League had three main organs. The Assembly included all member nations meeting annually, with each nation having one vote [1]. The Council was smaller, meeting more frequently, with permanent members (Britain, France, Italy, Japan) and elected temporary members [1]. Both required unanimous decisions for action, which made agreement difficult [1]. The Secretariat handled administrative work, while specialist agencies like the International Labour Organisation and Health Organisation addressed social issues [1].
Examiner guidance: Identify distinct structural features. Link structure to function where possible. Four developed points earn full marks.
Example 2: Why did the League of Nations fail to stop Italian aggression in Abyssinia? Explain your answer. [6 marks]
Model answer:
Britain and France prioritised keeping Italy as an ally against Hitler, so they undermined sanctions by excluding oil, the vital resource Italy needed for its war [1]. This lack of serious action meant Italy could continue military operations [1]. The Hoare-Laval Pact revealed that Britain and France were willing to reward Italian aggression by giving Mussolini two-thirds of Abyssinia, betraying League principles [1]. This destroyed any remaining credibility the League possessed [1]. Additionally, no League member would commit military forces to defend Abyssinia, demonstrating that collective security was meaningless [1]. The League had no army of its own and economic sanctions alone could not stop a determined aggressor [1].
Examiner guidance: Provide multiple developed reasons. Explain consequences of each reason. Link causes together where possible. Three well-developed reasons can achieve full marks.
Example 3: "The main reason the League of Nations failed was the absence of the USA." How far do you agree? Explain your answer. [10 marks]
Model answer structure:
Agreement paragraph: The USA's absence removed the world's strongest economy, making economic sanctions less effective. Japan could trade with the USA during the Manchurian Crisis, undermining League action. American membership might have deterred aggressors who saw a weak League without US support. US naval power in the Pacific could have changed the outcome in Manchuria.
Counter-argument paragraph: However, even with US membership, fundamental structural weaknesses would have remained. Unanimous decision-making paralysed rapid response. Britain and France dominated the League but lacked will to enforce collective security, prioritising their own interests over League principles. The absence of an international army meant reliance on reluctant members. The treatment of Abyssinia showed Anglo-French hypocrisy, not American absence, destroyed the League's credibility.
Judgment: While US absence weakened the League significantly, it was not the main reason for failure. The fundamental problem was that member nations, particularly Britain and France, were unwilling to risk their own security or resources to uphold collective security. This would have remained true even with American membership. The League failed because major powers abandoned its principles when faced with determined aggression.
Examiner guidance: Balanced argument addressing both sides. Use specific examples. Reach a clear, supported judgment. Higher marks require evaluation, not just description.
Common mistakes and how to avoid them
Confusing the League with the Treaty of Versailles: The League was created by the Treaty but was a separate organisation with broader aims than simply enforcing Versailles. Distinguish between Treaty terms and League actions.
Claiming the League achieved nothing: The League had genuine successes in the 1920s with territorial disputes and humanitarian work. Acknowledge these before explaining why it ultimately failed in the 1930s when faced with major powers.
Oversimplifying reasons for failure: Avoid single-cause explanations like "it failed because America wasn't a member." Address multiple factors including structural weaknesses, absence of enforcement powers, conflicting member interests, and the rise of aggressive dictatorships.
Writing narratively without analysis: Describing what happened chronologically earns few marks. Explain why events occurred and what consequences followed. Link events causally rather than simply listing them.
Ignoring the League's specialist agencies: Questions about League achievements require mentioning humanitarian and social work, not just political disputes. The Health Organisation, Slavery Commission, and ILO represent important successes.
Failing to distinguish between 1920s successes and 1930s failures: The League's changing effectiveness over time is crucial. Explain why it succeeded against small nations in the 1920s but failed against major powers in the 1930s.
Exam technique for "The 20th Century: International Relations since 1919 — The League of Nations"
Command words matter: "Describe" requires factual detail without explanation. "Explain" requires causes and consequences. "How far" or "To what extent" requires balanced argument with a supported judgment. Adjust your response accordingly.
Use the mark allocation strategically: A 4-mark question needs four distinct developed points. A 6-mark question typically requires three well-explained points or two very thoroughly developed ones. A 10-mark question demands multiple paragraphs with argument, counter-argument, and judgment.
Deploy specific evidence: Named examples (Manchuria, Abyssinia, Corfu), dates, key individuals (Mussolini, Haile Selassie, Lytton), and precise details (Hoare-Laval Pact, Mukden Incident) demonstrate knowledge and support arguments convincingly.
Address change over time: Questions often require explaining why the League succeeded in some cases but failed in others. Compare 1920s successes with 1930s failures, distinguishing between dealing with small nations versus major powers.
Quick revision summary
The League of Nations (1920-1946) aimed to maintain peace through collective security and arbitration. Structural weaknesses included absent members (USA, initially Germany and USSR), unanimous decision-making, no permanent army, and British-French dominance without commitment. The League succeeded in 1920s territorial disputes (Åland Islands, Upper Silesia) and humanitarian work but showed weakness at Vilna and Corfu. Catastrophic failures followed in Manchuria (1931-33) when Japan faced no real consequences, and Abyssinia (1935-36) when half-hearted sanctions and the Hoare-Laval Pact destroyed the League's credibility. By 1939, the League was irrelevant as Hitler's aggression went unchecked, leading to the Second World War.