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

During the early 1920s, Japan was a significant global power, which was largely due to its victories in the First Sino-Japanese War (1894-1895) and the Russo-Japanese War (1904-1905).

In 1919, Japan had joined the League of Nations as one of its founding members. It did so in order to be recognized as an equal among Western powers.

As the only non-Western member of the League’s permanent council, Japan aimed to use its membership to strengthen diplomatic ties and enhance its status in global politics.

It also advocated for racial equality at the Paris Peace Conference in 1919, but this proposal was rejected by the Western powers. 

By the mid-1920s, Japan had established itself as a key player in international diplomacy, which was demonstrated by its participation in the Washington Naval Conference of 1921-1922.

As part of the agreements, Japan was shocked by the Five-Power Naval Treaty, as it aimed to limit naval armament and maintain a balance of power among the world's naval forces.

Japan accepted restrictions on its fleet size, which was intended to promote stability but also limited its expansionist ambitions.

As tensions simmered beneath this diplomatic engagement, Japan continued to use the League as a platform to advance its strategic interests. 

Then, in 1927, Prime Minister Baron Tanaka Giichi reportedly outlined Japan’s desire to dominate East Asia, especially China.

According to a document known as the Tanaka Memorial, he outlined Japan’s growing need for resources and markets to fuel its industrial expansion.

While it presented itself as cooperative on the surface, Japan’s approach had become more aggressive, as economic pressures and political instability motivated a shift in Japan’s foreign policy.

By the late 1920s, its relationship with the League of Nations had become increasingly strained, especially as its ambitions in Manchuria began to clash with the League’s commitment to maintaining peace and upholding the territorial integrity of its members. 

Following the global economic downturn of the Great Depression, Japan’s economy, which was heavily dependent on international trade, faced severe challenges.

Its industries required vast amounts of raw materials like coal and iron, which had become increasingly scarce within Japan’s borders.

In comparison, the nearby region of Manchuria was rich in these essential resources.

By securing control over it, Japan believed it could fuel industrial growth and stabilize its economy.

In addition, Manchuria’s expansive agricultural lands promised relief for Japan’s food shortages, which had grown critical due to its surging population.  

On a strategic level, Japan saw Manchuria as a crucial buffer zone against potential threats.

As it bordered both the Soviet Union and China, Japanese military leaders believed it necessary for defending against Russian expansion in East Asia, especially after the tensions created by the Russo-Japanese War.

This control could also allow Japan to expand its sphere of influence deeper into mainland Asia.

Domestically, Japan believed that it could justify any future invasion by promoting the idea that it was liberating Manchuria from Chinese misrule.

Officials even began highlight their need to protect the rights of Japanese citizens living there.

This narrative struck a chord with the Japanese public, who increasingly supported the idea of a military intervention as a solution to the country’s economic challenges.

However, the Japanese government could not just invade without a reason, so it began planning a scenario that could justify a military intervention. 

On the evening of September 18, 1931, a small explosion occurred near the tracks of the South Manchuria Railway, just outside Mukden (now Shenyang).

Japanese officers in the area quickly blamed Chinese saboteurs. The explosion only caused minimal damage to the railway, and was later revealed to have been orchestrated by the Japanese military, but this was not known at the time.

Regardless, it gave the Imperial Japanese Army the excuse it needed to launch a swift and decisive invasion of Manchuria. 

Within days, Japanese forces overwhelmed Chinese troops, seizing key cities and securing control over the territory.

The Chinese government, which was already weakened by internal divisions and lacking modern military capabilities, could not mount an effective defense.

It was clear at the time that Japan's aggressive actions not only violated Chinese sovereignty but also directly challenged the League of Nations’ principles, which promoted collective security and peaceful dispute resolution.

As the invasion escalated, alarm spread throughout the international community, and the League of Nations felt compelled to intervene. 

By March 1932, Japan had established the puppet state of Manchukuo. On the international stage, Japan sought to defend its actions as a legitimate response to regional instability.

Diplomats argued that control of Manchuria would act as a way of preventing the spread of communism from the Soviet Union.

By intervening, Japan asserted its role as the rightful steward of the region. It was hoped that this defense would placate Western powers and the League of Nations. 

In December 1931, the League of Nations established the Lytton Commission, a special body tasked with investigating the situation.

It was led by British diplomat Lord Lytton and the commission included representatives from France, Germany, Italy, and the United States.

Over several months, the commission traveled to both Japan and China, gathering evidence and interviewing key officials.

By the time it returned in 1932, tensions had worsened as Japan continued solidifying its control over Manchuria.

The commission’s goal was to produce an impartial report to guide the League’s response, and the investigation became one of the most detailed inquiries the League had conducted in its efforts to address the crisis without escalating conflict. 

When the Lytton Report was submitted in October 1932, it condemned Japan's actions as unjustified and unlawful.

The report acknowledged China’s political instability, which had contributed to regional unrest, but firmly rejected Japan's claim that it had acted in self-defense.

The commission determined that Japan had staged the Mukden Incident and used it as a pretext for a full-scale invasion.

It recommended that Japan withdraw its forces from Manchuria and restore Chinese sovereignty.

In addition, it called for international mediation to resolve the conflict peacefully.

Importantly, the report did not recommend military or economic sanctions against Japan. 

Japan’s frustrations with the League of Nations began building long before the Manchurian crisis.

From the time it joined as a founding member, Japan felt sidelined by Western powers, who dominated the League’s decision-making process.

In 1919, during the Paris Peace Conference, Japan proposed a racial equality clause, which was overwhelmingly supported by several delegations.

However, key powers like the United States and Britain opposed the clause, resulting in its rejection.

This early experience solidified Japan’s view that the League operated with a Western bias, favoring European interests over those of non-Western nations. 

By the 1930s, Japan increasingly viewed the League as prioritizing Western agendas at the expense of its own strategic needs.

Military and political leaders, including figures like General Kanji Ishiwara and Prime Minister Tsuyoshi Inukai, believed the League failed to address Japan’s security concerns in East Asia.

The League’s condemnation of Japan’s actions in Manchuria, combined with what Japan perceived as a disregard for its vital interests, reinforced the belief that the League favored China and the Western powers.

This only deepened Japan’s isolation within the international community. 

As a result, Japanese officials began asserting that the League had no right to interfere in regional security matters.

They pointed to the Western powers, particularly Britain and France, who maintained vast colonial empires and often acted unilaterally in their territories.

To Japan, the League’s criticism of its actions in Manchuria appeared hypocritical.

The fact that Britain, France, and the United States had significant economic interests in China only added to Japan’s belief that these nations were more concerned with protecting their own investments than with maintaining global peace.

Japan’s decision to ignore the Lytton Report, which condemned its invasion of Manchuria, stemmed directly from this conviction that the League was not a neutral entity but an extension of Western dominance. 

In early 1933, tensions between Japan and the League of Nations reached a breaking point.

Following the Lytton Report’s condemnation of Japan’s actions in Manchuria, the League convened the Geneva Assembly to formally address the situation.

On February 24, 1933, the assembly gathered to vote on a resolution that supported the report’s findings, urging Japan to withdraw its forces from Manchuria and restore Chinese sovereignty.

An overwhelming majority of the 42 nations present supported the resolution, with only Japan voting against it.

The decision directly challenged Japan’s claim that it was acting to preserve peace in the region. 

At the Geneva Assembly, Ambassador Yosuke Matsuoka led Japan’s delegation and delivered a defiant speech in response to the vote.

Matsuoka accused the League of failing to understand Japan’s position and claimed that the organization was biased in favor of China and Western powers.

He firmly stated that Japan would not comply with the League’s demands, insisting that Japan’s actions in Manchuria were essential for its national security and economic stability.

Matsuoka’s forceful speech made it clear that Japan no longer saw itself as bound by the League’s decisions. 

So, on March 27, 1933, after weeks of diplomatic standoffs and growing isolation, Japan formally announced its withdrawal from the League of Nations.

Though the decision had been anticipated for months, the vote in Geneva and the continued condemnation of its actions solidified Japan’s resolve to leave.

Japan’s exit sent shockwaves through the international community, as it became the first major power to abandon the organization.  

Upon its withdrawal, Japan was no longer bound by the League’s resolutions or subjected to diplomatic pressure from the international community.

This newfound freedom allowed Japan to pursue its imperial ambitions in East Asia without external scrutiny.

Emboldened by the break, Japan’s leaders intensified efforts to expand territorial control, focusing on China.

Manchuria, already firmly under Japanese control, became the launching point for further incursions into northern China.

In 1937, Japan launched a full-scale invasion of China. As a result, Japan's foreign policy shifted decisively toward militarism, with the military increasingly influencing government decisions. 

As a result, Japan became increasingly isolated on the world stage, particularly from Western powers like Britain and the United States.

By 1940, Japan announced that it had entered into the Tripartite Pact with Germany and Italy, which aligned itself formally with the Axis Powers.  

For the League of Nations, Japan’s departure exposed its weaknesses. Founded on the principle of collective security, the League failed to prevent a major power from defying its resolutions.

The lack of resolve in enforcing its decisions during the Manchurian crisis and Japan’s withdrawal severely damaged the League's credibility.

Other nations observed this failure, which undermined confidence in the League’s capacity to maintain international order.

As a result, further acts of defiance followed, including Italy’s invasion of Ethiopia in 1935.

The League’s inability to address such crises signaled its decline as an effective peacekeeping body, and by the time World War II erupted, it had become largely irrelevant in global diplomacy.