Japan’s Motivation for Attacking Pearl Harbor

Painting of a Pearl Harbor-style attack.
Japanese aircraft flying over South East Asia.
Territories controlled by Japan in 1942 shown in gren. Japan itself is shown in dark green.
Aerial view of modern-day Pearl Harbor, Hawaii.

As Germany was taking over neighboring countries in Europe at the beginning of World War II, Japan was doing the same thing in East Asia. Japan’s aggressive stance towards its neighbors, quite expectedly, made much of the world angry, and caused the United States to embargo shipments of oil to the country as a punitive measure in 1941. This left Japan, whose planes and ships depended on gasoline, in dire need of the black gold.

Aware that there were plenty of oil and other raw materials in the Dutch East Indies and the Philippines, the Japanese now decided to invade these territories. However, though located in Southeast Asia, the Dutch East Indies and the Philippines were Dutch and American colonies and protectorates, making them extra dangerous for Japan to invade, since doing so would likely prompt a Western military response.

Attacking Hawaii

Suspecting that an invasion of the American-controlled Philippines would lead to war with the United States, Japan, before invading the Philippines to snatch its raw materials, opted to pre-emptively strike the United States’ Pacific Fleet in Hawaii. This attack, subsequently, was carried out in the morning of December 7, 1941. Pearl Harbor in Hawaii, where the U.S. Pacific Fleet was stationed, come the morning of the assault, was taken by surprise, and hundreds of American aircraft and several warships were destroyed.

The attack on Pearl Harbor, as the Japanese had expected, resulted in U.S. President Franklin Delano Roosevelt declaring war on Japan on December 8 1941. Because Japan was allied with Germany, and German leader Adolf Hitler declared war on the United States only days later, the U.S. now also became drawn into the conflict in Europe.