Answer:
The Japanese invasion of Manchuria
Step-by-step explanation:
Japan's first aggressive move in the early 1930s was the invasion of Manchuria, located in northeastern China. This event occurred in 1931, when Japanese soldiers seized the city of Mukden (now Shenyang) in Manchuria, claiming that Chinese troops had attacked Japanese railway lines in the region. As a result of this invasion, a Japanese-controlled puppet state was established in Manchuria, which was known as Manchukuo and led by the last Qing emperor, Puyi. The invasion of Manchuria was the initial step in Japan's expansionist policy in East Asia and ultimately resulted in its participation in World War II.