On September 18, 1931, several packages of blasting powder were detonated on the South Manchuria Railway. The Kwantung Army blamed the Chinese for this, and used it as an excuse to invade Manchuria, launching a series of events which would culminate in the rise of militarism in Japan.
SOURCES:
Japan's Total Empire, Young
Ishiwara Kanji's Confrontation with the West, Peattie
The Japanese Colonial Empire, Peattie
The Making of Japanese Manchuria, Matsusaka
