Why Was Pearl Harbor Attacked?

When people are learning about Pearl Harbor, they often ask: why was Pearl Harbor attacked? Before the attack, World War II was only being fought in Europe. So why did the Japanese decide to attack the United States?

To better answer this question, it’s helpful to learn about the events that led up to the terrible attack on December 7, 1941.

The European War

Before the attack on Pearl Harbor, the world was not at peace. On September 1, 1939, Germany’s leader, Adolph Hitler, took over the country of Poland. Germany had angered the British and French earlier by taking over Austria and Hungary. However, the attack on Poland was the breaking point. The British and French declared war on Germany, saying the takeovers had to stop. That was the beginning of World War II, which would soon spread around the world.

The United States was on the same side as Britain, France, and Poland (the Allies) at the time, but many Americans wanted to stay out of all foreign conflicts. US President Franklin D. Roosevelt wanted to support the Allies. However, he had a hard time convincing Congress and the American public that the US should go to war. Instead, he started a program in March 1941 to help the Allies. Called the Lend-Lease Act, the program gave him great power to control money and supplies to help the Allies.

Distrust between the US and Japan

It’s hard to image the United States ever fighting with Japan, but before the attack, the two countries did not trust each other.

We often think of 1939 as the start of World War II. In fact, earlier events helped set the stage for war. When Japan declared war on China in 1937 (the beginning of the Second Sino-Japanese War), the United States lost trust in Japan. Over time, the Japanese treated their Chinese prisoners worse and worse. They committed terrible acts against the Chinese, including killing prisoners without allowing them to have trials.

The United States did not send soldiers to try to stop Japan. Instead, the US stopped selling the Japanese certain goods, including iron, steel, and oil, to try to force them to stop. The Japanese, however, did not change their minds. Instead, they stood even more firmly.

Although leaders in Tokyo and Washington tried to find some point of agreement, the relationship between the US and Japan did not improve. It seemed that war would be the only answer.

Why Pearl Harbor?

Very few military officials believed that the Japanese would directly attack the US, especially in Hawaii. The naval base and Japan were 4,000 miles apart. These days, we might not think that distance is very far, but back then it was a long, difficult flight. American officials who were monitoring coded Japanese messages were certain that European colonies in Southeast Asia were more at risk than Pearl Harbor.

That belief led to another big mistake. Because no one believed Pearl Harbor would be attacked, it was left mostly unguarded. Most of the Pacific Fleet was there on that fateful morning, a fact that seemed too good to be true for the Japanese.

As it turned out, it was too good to be true. On December 8, 1941—the day after the attack—President Roosevelt declared war on Japan and her allies Germany and Italy. The US began sending troops overseas, turning the tide of war in favor of the Allies at last.

Hopefully now you have a better understanding of why Pearl Harbor was attacked, and you’ll be able to enjoy your tour a bit more.