4. The Japanese Invasion of Manchuria (1931)
The Japanese invasion of Manchuria in 1931 began with the Mukden Incident, where Japanese forces staged an explosion on the South Manchurian Railway to justify military action. Within months, Japan established the puppet state of Manchukuo, exploiting the region’s resources and disrupting Chinese sovereignty. This aggressive expansionism intensified regional tensions, leading to the Second Sino-Japanese War in 1937 and contributing to the broader conflicts of World War II. (history.com)
