Why Did the League of Nations Ultimately Fail?

World War I convinced Allied leaders of the need for an international body to prevent future wars. Why did this body–The League of Nations–fail by the late 1930s?

May 6, 2023By Owen Rust, MA Economics in progress w/ MPA

league of nations fail


The world’s first attempt at a globe-spanning international body to promote peace and diplomacy was The League of Nations. In the aftermath of World War I, the victorious Allied powers were determined to prevent such bloodshed from ever occurring again. US President Woodrow Wilson arrived at the Paris Peace Conference in 1919 with the idea of a formal league of nations. Though noble and innovative, the idea was quickly hit with skepticism from other American and foreign leaders. After its establishment in 1919, the League of Nations struggled to accomplish its lofty goals of preventing conflict. Why was it unsuccessful, leading to the outbreak of World War II?


Setting the Stage: World War I

A photograph of damage in France caused by World War I, via the National WWI Museum and Memorial, Kansas City


World War I (1914-1918) was like no war before it, with industrialized weaponry and new trench warfare tactics leading to death and destruction on an unimaginable scale. For four years, modern weapons like the machine gun, chemical warfare, and accurate artillery turned battlefields into indiscriminate killing fields. Only in 1918 was the stalemate of trench warfare on the western front in France broken, with Germany wagering that its recent victory against Russia would give it enough manpower from the eastern front to defeat the combined forces of France, Britain, and the United States.


Fortunately for the Allied Powers, the addition of American soldiers held the line. The Allies withstood Germany’s Spring Offensive and responded with their own Hundred Days Offensive, which led to Germany requesting an armistice. Unable to continue the war, Germany hoped to receive acceptable terms for peace after its call for a truce in November 1918. However, the tremendous devastation to regions of France left many Allied leaders wanting harsh punishments for Germany.


Setting the Stage: The Paris Peace Conference

An image of European leaders at the Paris Peace Conference of 1919, via the Ivy League Model United Nations Conference (ILMUNC)


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To hammer out the terms for peace, Allied leaders agreed to meet in Paris. However, each delegation had its own idea of what the post-war peace would look like. France, which had suffered the most war devastation, wanted harsh punishments for Germany. The United States, which had entered the war late, wanted a fair deal that would not leave Germany feeling embittered and potentially looking for revenge. Britain was somewhere between the two. Italy, which had switched sides from being a Central Power to an Allied Power in 1915, hoped to gain some territory from Germany’s defeated ally, Austria-Hungary.


The conference, which began in January 1919, was full of complications. Only Britain and France had been Allied Powers from the outbreak of the war, and the United States was technically a co-belligerent fighting on the side of the Allies. Russia had been an ally from the outbreak of the war but had left the war in March 1918 with the Treaty of Brest-Litovsk, which ceded much territory to Germany. The Central Powers were excluded from the conference and would essentially be handed the treaty when it was completed.


Woodrow Wilson’s Fourteen Points

A photo of US President Woodrow Wilson, who proposed Fourteen Points of post-World War I international law, via The Woodrow Wilson Presidential Library and Museum, Staunton


One man entered the Paris Peace Conference as a relative celebrity: US President Woodrow Wilson. An idealist, Wilson brought with him a plan for post-war peace that would benefit all parties. His Fourteen Points declared that all parties should accept no secret treaties, freedom of navigation on the high seas, sovereignty for Poland, and the creation of “a general association of nations.” Publicly, there was strong support for the formation of a general association of nations, which would put diplomacy first and prevent future wars.


However, the other Allied leaders at the conference were not as interested in Wilson’s idealism. Britain, with its world-leading Royal Navy, was not keen on free navigation of the seas by all nations. France wanted harsh punishments, specifically war reparations, for Germany and thought Wilson was too generous to their defeated foe. However, Wilson remained adamant about the importance of his fourteenth and final point, the League of Nations, and it was included in the conference’s ultimate creation of the Treaty of Versailles. The treaty was signed on June 28, 1919, officially ending World War I.


Skepticism of the League in the US Senate

A political cartoon from 1920 showing a partisan battle between Woodrow Wilson (left) and US Senator Henry Cabot Lodge (right), via The Ohio State University


While the Treaty of Versailles was signed, it would not become law for the United States until it was ratified by a ⅔ majority in the US Senate. Unfortunately for President Wilson, a Democrat, the Senate was controlled by the Republicans. Wilson had not brought any Republicans to the Paris Peace Conference, and many thought he was being disrespectful by simply expecting the Senate to ratify the Treaty of Versailles with little negotiation. The chief opponent of ratification was US Senator Henry Cabot Lodge (R-MA), the Senate Majority Leader.


Despite public support in the United States for the League of Nations, Lodge opposed it on the grounds that it would weaken US sovereignty. He declared that joining the League would violate the famous advice given by first President George Washington in his Farewell Address of 1796, which was to avoid foreign political entanglements. Lodge argued that joining the League would force the US to intervene militarily “at a moment’s notice” abroad and would subject the US to open immigration from other League member nations. Having just experienced the horrors of World War I and facing a wave of anti-immigration sentiment due to post-war radicalism, many senators did not want to risk more potential upheaval by joining the League.


The League is Formed…But America Sits Out

A famous political cartoon criticizing the United States for not joining the League of Nations, via Ashland University


The Treaty of Versailles, which contained a clause that would require the United States to join the League of Nations, failed ratification in two separate votes in 1919 and 1920. It was the first time in US history that the Senate had refused to ratify a peace treaty. Woodrow Wilson suffered a severe stroke in autumn 1919 while on a nationwide speaking tour to promote the League of Nations, leaving him bedridden for months. Wilson’s incapacitation kept him from pushing for another Senate vote on the Treaty of Versailles and also kept him from contention for a third term as president. When Wilson was not considered for a third presidential term by the Democratic Party, the United States had moved past any realistic chance of joining the League of Nations.


Despite the US not joining, thirty-two other nations did join the League. The organization formally launched in 1920.  However, the absence of the United States was quickly felt because the former Allied Powers–France, Britain, and Italy–were numerically matched by the former Central Powers–Germany, Austria-Hungary, and Turkey–from World War I. Russia, another former member of the Allied Powers, was not invited to join the League because it was in the midst of the bloody Russian Civil War. Thus, votes about disarmament and other matters saw the former Allied and Central Powers deadlocked in ties.


Nations Ignore League Rules

A map showing the results of the 1931 invasion of Manchuria, a region of northeastern China, by Japan, via the University of Rochester


Despite a formal structure that included a Council of powerful founding members, the League was not effective at preventing military aggression. Confined largely to its headquarters in Geneva, Switzerland, the organization had no physical power of its own. Before long, member nations were simply defying the rules and expectations of the League. Despite being a permanent member of the Council, Japan simply left the League after being condemned for its 1931 invasion of the Manchuria region of northeastern China. Despite the appeals of China, a fellow member of the League, for assistance, the organization refused to subject Japan to economic sanctions.


The two most powerful initial members of the League (before Germany joining in 1926 and the Soviet Union joining in 1934) were Britain and France. However, due to the high costs of World War I, neither nation wanted to devote many resources toward League-related peacekeeping. Physical peacekeeping required armies, though member states were not required to offer them. This made any physical strength of the League of Nations entirely voluntary, and it seemed that no nation wanted to volunteer its resources and soldiers to stop aggressor states, especially during the economic woes of the worldwide Great Depression.


The League of Nations Versus Rising Fascism

Italian dictator Benito Mussolini (left) and German dictator Adolf Hitler (right) brought fascism to Europe in the 1930s, via Radio Free Europe


Although the League did have some small diplomatic successes in the 1920s, such as negotiating territorial disputes between European nations, it could not contain the aggression of communist Russia (which became the Soviet Union in 1922) or fascist states like Italy, Germany, and Japan. The rise of fascism began with Italian prime minister Benito Mussolini, who evolved into a one-party dictator by 1925. Surrounded by smaller states like Greece, Albania, and Yugoslavia, Italy frequently sought to gain territory, with Mussolini allegedly wanting to return his nation to the glory of the Roman Empire.


To the north, Germany suffered political and economic instability throughout the 1920s. By 1933, however, Nazi party leader Adolf Hitler was appointed chancellor by ailing president Paul von Hindenburg. Economic woes and fears of communism led many Germans to support the fascist Nazi party, which pledged to return Germany to its former glory. Nine months after Hitler became chancellor, Germany exited the League of Nations to embark on rearmament. With Germany no longer a member of the League, there was little the body could do to prevent its march toward militarism.


Italy Invades Ethiopia

A photograph of Ethiopian soldiers in the mid-1930s, who would be fighting against the invading forces of fascist Italy in the Second Italo-Ethiopian War (1935-37), via the Ethiopian Tribune


Japan’s 1931 invasion of Manchuria had tested the League’s resolve, and the League had failed to act. In 1935, the League faced a second similar crisis. Italy, now firmly led by dictator Benito Mussolini, invaded Abyssinia (today known as Ethiopia) on October 3. Abyssinia was one of only two independent nations in Africa, and the world watched anxiously as it fought bravely against a European power. Although the League condemned Italy as the aggressor, it did not move quickly toward applying economic sanctions. By the time the League decided to ban oil exports to Italy in February 1936, Ethiopia was facing defeat.


In retaliation to the economic sanctions, Italy left the League of Nations in December 1937. With Japan, Germany, and Italy no longer members of the League, there was little to stop their march toward military aggression. Nations like Britain began their own rearmament programs, potentially in violation of the League as well. The prevailing belief by the late 1930s was that the League, although noble in design, was not equipped to reign in rising powers like Germany, Italy, and Japan. Thus, other nations should also develop their militaries in preparation for conflict.


World War II Leads to the Final End of The League

A map showing the greatest extent of Axis Power control in Asia and the Pacific in June 1942, via the National WWII Museum in New Orleans


The swift eruption of World War II in Europe in September 1939 proved too much for the League, as aggressor nation Germany was not a member of the body. That December, the Soviet Union was expelled from the League for its invasion of neighboring Finland in the Winter War, marking perhaps the last noteworthy action of the organization. With war raging across Europe, it seemed clear that diplomacy had failed. The following spring, Germany struck again and defeated France in only six weeks, shocking the globe. A year later, Germany invaded the Soviet Union, expanding the war drastically.


Between 1939 and 1945, the Palace of Nations in Geneva, Switzerland sat empty. The League had failed to prevent the start of the war, and diplomacy would not end it. Having learned a painful lesson from World War I, where Germany was allowed to end the war by armistice rather than surrender, the Allied Powers of World War II declared that unconditional surrender was the only acceptable fate for Germany and Japan. The fear was that allowing Germany or Japan to end the war diplomatically might simply be a ploy to give those nations time to re-arm, after which they would strike again. Japan was only convinced to surrender unconditionally in August 1945 after two atomic bombs created by the Manhattan Project were dropped on Hiroshima and Nagasaki, destroying both cities.


Legacy of The League: The United Nations (1945-)

A photograph of Uruguay joining the new United Nations during the San Francisco conference of 1945, during which time some 50 nations joined, via the United Nations


On April 26, 1946, the League of Nations officially disbanded and transferred all of its assets to a new organization, the United Nations. The United Nations, or UN, was officially established on October 24, 1945. Unlike the League, the UN was created with all major Allied Powers from the preceding war as members: both the United States and the Soviet Union were founding states. Today, almost all nations in the world are part of the UN, including perennial troublemaker North Korea. The only nation-state of any considerable size or economic power that is not a member is Taiwan (Republic of China), which was replaced as the legal entity for China in the UN by the People’s Republic of China in 1972.


A large map showing League of Nations members as of 1927, via Dr. Laura H. Martin and Boston Rare Maps


Today, the UN continues all of the same roles as the original League of Nations. Unlike the UN, it has stronger mandates for peacekeeping and has almost 100,000 military personnel from 120 member nations. UN Peacekeepers are known for their blue helmets and have protected civilians and UN humanitarian personnel in many crisis spots since 1948. Aside from peacekeeping, the UN performs a wide range of humanitarian work and scientific research in the areas of climate change and international health. Instead of Geneva, Switzerland, the UN is headquartered in New York City but has sites and offices around the world.

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By Owen RustMA Economics in progress w/ MPAOwen is a high school teacher and college adjunct in West Texas. He has an MPA degree from the University of Wyoming and is close to completing a Master’s in Finance and Economics from West Texas A&M. He has taught World History, U.S. History, and freshman and sophomore English at the high school level, and Economics, Government, and Sociology at the college level as a dual-credit instructor and adjunct. His interests include Government and Politics, Economics, and Sociology.