Answer:
There were several signs of early Japanese aggression leading up to World War II. These included:
Invasion of Manchuria: In 1931, Japan invaded the Chinese province of Manchuria, which led to the establishment of the puppet state of Manchukuo. This was a clear violation of China's sovereignty and a sign of Japan's expansionist ambitions.
Occupation of Inner Mongolia: In 1933, Japan occupied the Inner Mongolian region of China, further encroaching on Chinese territory.
Invasion of China: In 1937, Japan launched a full-scale invasion of China, beginning the Second Sino-Japanese War.
Expansion into Southeast Asia: In the late 1930s, Japan began to expand its influence in Southeast Asia, occupying and annexing various territories in the region.
Japanese Premier Tojo Hideki decided to attack Pearl Harbor for several reasons. One major reason was that the U.S. had imposed economic sanctions on Japan, cutting off access to vital resources such as oil. The attack on Pearl Harbor was meant to cripple the U.S. Pacific Fleet, allowing Japan to conquer the resource-rich territories of Southeast Asia without interference from the U.S.
Strategically, Pearl Harbor was a prime target for an attack by Japan because it was the home of the U.S. Pacific Fleet, which posed a threat to Japan's plans for expansion in the region. Attacking the Pacific Fleet at Pearl Harbor would allow Japan to gain control of the Pacific Ocean and secure its hold on the territories it had already conquered.