The explosive events that led Japan to storm out of the League of Nations in 1933

After 1919, Japanese leaders had begun to expect the postwar system to recognise their country’s status as a great power.

At the Paris Peace Conference, Japan sat among the victorious Allied states and accepted membership as a founding nation of the League of Nations in January 1920.

Within that organisation, Japan secured a permanent seat on the League Council alongside Britain and France, with Italy also recognised as a permanent member, which gave it an official role in international decisions.

At the same time, Japanese representatives attempted to include a clause that called for racial equality among member nations, which aimed to secure recognition of Japan’s global standing.

However, the rejection of this proposal by Britain, Australia, and others produced widespread anger in Japan, where many saw it as proof that Western states still viewed non-European nations as inferior.

Despite this, Japanese officials accepted the Treaty of Versailles and initially retained control of the former German territory in Shandong, which they had seized during the First World War in 1914.

Under international pressure, especially from the United States, Japan agreed to return Shandong to China in 1922 as part of the Washington Conference agreements.

The League later confirmed Japanese control over former German islands in the Pacific north of the equator.

While this gave Japan clear benefits, it did little to ease concerns that its future interests would be ignored by its supposed allies.

Over the next decade, the League’s decisions increasingly failed to satisfy Japanese expectations.

Although civilian politicians continued to support diplomacy and cooperation based on treaties, officers in the army and navy questioned the League’s authority.

They believed it supported Western interests and got in the way of Japan’s ability to defend its security or secure access to the resources it lacked.

As nationalist voices grew louder, these frustrations influenced how Japan responded to foreign criticism during the Manchurian crisis.

After the First World War, Japan had experienced major social and economic pressures that had pushed it toward more controlling policies at home and more aggressive policies overseas.

In rural areas, farmers struggled under heavy debts and low rice prices, while industrial workers in urban centres faced low wages and periodic unemployment driven by inflation.

Then, the 1923 Great Kantō earthquake struck with incredible force, so much so that it destroyed much of Tokyo and Yokohama, killing over 100,000 people, and placed serious strain on the national budget.

By the end of the decade, the global depression triggered by the 1929 Wall Street Crash reduced demand for Japanese exports, especially silk, and caused unemployment to rise sharply.

Silk alone had accounted for 40% of Japan’s export earnings, and its collapse triggered many layoffs and business failures.

As economic pain spread, many citizens increasingly lost faith in democratic parties, which they saw as weak, corrupt, or under the influence of foreign interests.

Within the military, particularly among the officer corps of the Kwantung Army, this unhappiness had aligned with long-standing views that Japan needed to secure its own future without foreign approval.

Manchuria appeared to offer a possible solution, as it held valuable coal and iron deposits alongside important agricultural resources, and it lay on Japan’s doorstep.

With a population of over 30 million and a railway network that continued to grow, the region also promised the prospect of new jobs and better defence in case of attacks that might come from abroad.

Moreover, it provided a buffer between the Japanese Empire and potential threats that could come from China or the Soviet Union.

Although the Tokyo government had signed treaties such as the Washington Naval Treaty and the Kellogg–Briand Pact, which aimed to limit conflict, military leaders increasingly dismissed such agreements as obstacles.

Instead, they viewed Manchuria as a region where Japan could act decisively, without waiting for civilian permission or League approval.

On 18 September 1931, officers in the Kwantung Army staged an explosion on the South Manchurian Railway near Mukden and blamed it on Chinese saboteurs.

The damage was minimal, yet the army used the event to justify a complete military occupation of Manchuria.

Over the next few weeks, Japanese forces captured important towns and railway hubs without formal orders from Tokyo.

Though the civilian government protested, it failed to stop the military advance.

Prime Minister Inukai Tsuyoshi had attempted to restrain the army and he was assassinated in May 1932, which eliminated a key supporter of civilian control.

In March 1932, Japanese authorities declared the establishment of Manchukuo, a puppet state whose ruler was the former Qing emperor Puyi.

According to official statements, officials claimed that Manchukuo expressed the will of its people, but, in reality, it operated under Japanese military control and had no independent diplomatic authority.

Japanese administrators introduced its own currency and flag to present the appearance of independence.

Shortly after, the Chinese government appealed to the League of Nations, and it accused Japan of violating both the League Covenant and the Kellogg–Briand Pact.

The Chinese delegation was led by Wellington Koo and it strongly argued that Japan had committed open aggression.

To deal with the crisis, the League appointed a commission led by Lord Lytton, which travelled to Manchuria to investigate.

Over several months, the commissioners had interviewed officials and had observed military movements as they examined the way in which the region was run.

The Lytton Report was published in October 1932 in which it concluded that Japan had real concerns about banditry and instability, but that the invasion violated international agreements and that Manchukuo did not have the features of an independent state.

Soon after the report’s publication, Japanese troops launched a further offensive into Jehol province, which lay outside the limits of Manchuria, which clearly undermined Tokyo’s claims that it had acted only to stabilise the railway zone.

At home, press campaigns often depicted the League as hypocritical, and they pointed out that Britain and France, along with other imperial powers, held colonial empires across Asia and Africa that faced no criticism.

The idea that Japan alone was being judged fuelled nationalist anger and increased support for the military’s actions. 

On 24 February 1933, the League of Nations Assembly met to vote on the findings of the Lytton Commission.

After lengthy debate, forty-two member states voted in favour of the report’s recommendations, which rejected Japan’s claim that Manchukuo represented an independent state.

Japan cast the only vote against the report, although several states chose to abstain.

Immediately after, Foreign Minister Yosuke Matsuoka led the Japanese delegation as they walked out of the assembly chamber.

During his speech, he denounced the League for failing to understand Japan’s situation and warned that no nation would accept serious criticism it saw as unfair.

Then, on 27 March 1933, Japan formally notified the League of its withdrawal.

According to League procedures, the resignation would take effect two years later, though Japan had already ended its participation, and across the country, many newspapers celebrated the decision as an expression of national pride.

In military circles, the withdrawal effectively removed what many officers saw as the last diplomatic limit on expansion into China, and senior officers pressed ahead with plans for further advances.

Emperor Hirohito made no public attempt to restrain these moves, and this further showed a shift in power towards the armed forces.

At the League’s headquarters, member states gave statements of concern that did not lead to any sanctions.

Neither Britain nor France showed interest in taking military action against Japan, and without the United States, the League had no power to enforce its decisions.

Japan’s successful refusal to obey had helped encourage similar actions elsewhere.

By October 1933, Germany under Hitler had also left the League, and in 1935, Mussolini’s Italy invaded Ethiopia and largely dismissed League protests, as they knew that they would not face serious punishment.

The Soviet Union had observed these developments and it joined the League in 1934 in an attempt to strengthen collective security, but by then, its influence had already begun to fade.