It urged Japanese troops to withdraw from the occupied lands. The League of Nations carried out an investigation of the incident and concluded that Japan had, without a declaration of war, forcibly seized and occupied a large section of Chinese territory. The following year, this conquered territory was transformed into a Japanese puppet state, Manchukuo (1932–1945), under the nominal leadership of the last emperor of China, Pu Yi. Japanese aggression began with the seizure of Manchuria from China in September 1931.
The United States, the United Kingdom, the Soviet Union, and the Republic of China, represented significant obstacles to this expansion. Since the 1930s, the Japanese government had increasingly come under the influence of right-wing military leaders seeking to create a larger Japanese empire on the Pacific Rim. Background: Why did the Attack on Pearl Harbor Happen? Japanese Territorial Expansion in the 1930s It is located on the Hawaiian island of Oahu. Pearl Harbor was, and still is, the most important American naval base in the Pacific and home to the US Pacific Fleet. This unprovoked attack brought the United States into World War II, as it immediately declared war on Japan. Roosevelt claimed would “live in infamy,” the Imperial Japanese Navy conducted a surprise aerial assault on Pearl Harbor.
On December 7, 1941, a date that President Franklin D.
