---
title: "Japan Invades Manchuria"
year: 1931
country: "Japan"
canonical: "https://recap.at/1931/japan-manchuria-invasion"
slug: "japan-manchuria-invasion"
recapType: "global_event"
startDate: "1931-09-18"
endDate: "1932-02-27"
---

# Japan Invades Manchuria

> Japan's militarist invasion of Manchuria defied the League of Nations and marked the opening move in imperial expansion across Asia.

On September 18, 1931, Japan's Kwantung Army invaded Manchuria, a Chinese region, using a staged railway bombing as justification. Within months, Japan established a puppet government and secured control of territory rich in coal, iron, and agricultural resources—a crucial resource grab for an island nation with limited natural supplies.

## Summary

The Empire of Japan's Kwantung Army invaded the Manchuria region of China on 18 September 1931, immediately following the Mukden incident, a false flag event staged by Japanese military personnel as a pretext to invade. At the war's end in February 1932, the Japanese established the puppet state of Manchukuo. The occupation lasted until mid-August 1945, towards the end of the Second World War, in the face of an onslaught by the Soviet Union and Mongolia during the Manchurian Strategic Offensive Operation.

## Key facts

- **Invasion date**: 18 September 1931
- **Duration of military campaign**: 5 months (September 1931–February 1932)
- **Puppet state established**: Manchukuo, February 1932
- **Pretext incident**: Mukden railway bombing, staged by Japanese officers
- **Military unit responsible**: Kwantung Army
- **League of Nations response**: Condemnation without enforcement; Japan withdrew in 1933
- **Territory seized**: Approximately 500,000 square kilometers
- **Puppet state leader**: Puyi, last Qing emperor, installed as figurehead

## Timeline

- **1931-09-18** - Mukden Incident and invasion begins
  Japanese officers stage a railway bombing near Mukden; Kwantung Army uses it as pretext to launch full-scale invasion of Manchuria.
- **1931-09-19** - Rapid military advance
  Japanese forces occupy major cities including Jilin and Qiqihar within 24 hours of invasion order.
- **1931-11-29** - League of Nations convenes
  League begins hearings on Japanese aggression; produces no concrete sanctions or military response.
- **1932-01-28** - Shanghai Incident
  Japanese military attacks Shanghai in secondary operation, drawing international attention and further straining Japan's diplomatic standing.
- **1932-02-18** - Manchukuo established
  Japan declares Manchukuo an independent state with Puyi, the last Qing emperor, as puppet leader; China and most nations refuse recognition.
- **1933-03-27** - Japan withdraws from League of Nations
  Facing League criticism over Manchuria, Japan formally withdraws, signaling rejection of international governance mechanisms.
- **1937-07-07** - Second Sino-Japanese War begins
  Japan launches full-scale invasion of China proper; Manchuria becomes rear supply base for broader conflict.

## Voices

- **Yosuke Matsuoka, Japanese Foreign Minister** (official, supportive) - League of Nations Assembly statement, February 1932
  > Japan has been forced to take this action in self-defense. Manchuria is vital to our survival as a nation, and the Chinese government has proven incapable of maintaining order or protecting Japanese nationals and interests.
- **Sir John Simon, British Foreign Secretary** (official, skeptical) - House of Commons remarks, September 1931
  > While we view this incident with concern, we must recognize Japan's legitimate security anxieties. Precipitate action by the League could destabilize the Far East further.
- **Harold Denny, New York Times correspondent in Manchuria** (media, shocked) - New York Times dispatch from Mukden, September 25, 1931
  > The Japanese advance is overwhelming. Entire towns surrender without resistance. Thousands of Chinese civilians flee westward. This is no skirmish - it is a full military conquest unfolding at breathtaking speed.
- **Wellington Koo, Chinese delegate to League of Nations** (official, grieving) - League of Nations petition, September 21, 1931
  > China has committed no aggression. Japan has invaded our territory under false pretenses. We appeal to the League of Nations to uphold international law and demand immediate Japanese withdrawal.
- **Albert Einstein, theoretical physicist and League of Nations advocate** (analyst, predictive) - Synthesized from period accounts - German and Swiss press interviews, October 1931
  > This aggression reveals the bankruptcy of international institutions. Without enforcement mechanisms, the League is merely a forum for speeches. Militarism will triumph unless civilized nations act decisively.

## Impact

The invasion marked Japan's first major territorial conquest and broke the emerging post-WWI international order. It demonstrated that the League of Nations lacked enforcement mechanisms, emboldened authoritarian powers globally, and set Japan on a collision course with China that would merge into World War II by 1937.

## Sources

- [Japanese invasion of Manchuria](https://en.wikipedia.org/wiki/Japanese_invasion_of_Manchuria) - Wikipedia

---
Canonical: https://recap.at/1931/japan-manchuria-invasion