What did Japanese do in 1931?

In 1931, Japan invaded Manchuria, a region in northeastern China, following the Mukden Incident, which was a staged event used as a pretext for military action. This invasion marked the beginning of Japan's aggressive expansion in Asia and led to the establishment of the puppet state of Manchukuo. The occupation sparked international condemnation and set the stage for further conflicts in the region, contributing to the escalating tensions that would lead to World War II.