The Complicated Lead Up to Pearl Harbor

Curator Laurence Burke took a step back and explored the long and complicated history that led up to the Japanese attack.

Burke, to an audience outside the Museum’s Sea-Air Operations gallery, said the story of Pearl Harbor often focuses on the events of December 7, 1941, but not what happened before the day that President Roosevelt called, “a date which will live in infamy.”

To understand Pearl Harbor, Burke took the audience back to 1853-1854 when U.S. Naval Captain Matthew C. Perry sailed to Japan and negotiated the opening of Japanese ports for trade. After more than 200 years of self-imposed isolation, Japan wanted to engage with the rest of the world.  

To compete globally, Japan needed resources—a theme that persistently pushes the narrative of Pearl Harbor to its climax. Iron and coal were key natural resources in the steam era at the end of the 19^th century, but were not available in any significance on the Japanese island. Japan needed to look elsewhere.

Japan engaged in war in 1894-5 with China and in 1904-5 with Russia to secure resources. It was a 1905 win against the Russian Navy that shocked the world and alerted the U.S. that they needed to be prepared for a potential war with Japan.

As early as 1911, the U.S. Navy drafted plans for dealing with a possible war with Japan, known as War Plan Orange. The 1921 Washington Naval Treaty set out to prevent expensive naval building races between nations, but limited Japan to a much smaller navy than the U.S., a result that further soured the relationship between the two countries.

In September 1940, Japan aligned with Germany and Italy. Japan hoped the war would result in a boon of new resources and saw the alignment as a way to push back against the U.S. If America wanted to declare war on Japan, they would also have to declare war on Germany meaning a fight across two oceans.

In the summer of 1941, Japan moved to take the rest of Indochina. This aggression launched major diplomatic negotiations between Japan and the United States that would continue up until the attack on Pearl Harbor. While the U.S. had put embargoes on Japan in the past, in 1941 it completely froze all trade with Japan. This cut Japan off from key resources like scrap iron and petroleum.

The U.S. believed that Japan would run out of necessary resources in six months and would have to agree to negotiations or cease military action. Japan did the same math and realized they needed to act. Japan began to plan the attack on Pearl Harbor.

“This is not a unanimously acclaimed idea,” Burke noted. Many within the Japanese military were wary of the risks—Japanese carriers did not have the range to make it to Pearl Harbor and would need to refuel at sea, a maneuver that was unfamiliar to their navy. But to Japan, the potential reward outweighed the risks. They believed an attack on the U.S. would prevent America from entering the war for up to six months. In that time, Japan could shift the balance of power and take Malaya and the Dutch East Indies. Japan also hoped the attack would demoralize the United States into inaction. 

The Japanese Marshal Admiral Isoroku Yamamoto knew that to be successful secrecy was key. Few within the military were aware of what was conspired. Japanese carriers would take an extremely northern path to avoid shipping routes, and while travelling they were under complete radio silence. Even ship-to-ship communication was done using flags or blinker lights.

The final orders to attack Pearl Harbor were delivered to the ships by hand before they sailed on November 26th.

Burke noted that, at the time, the U.S. had only broken Japan’s diplomatic codes, not their naval codes. But even if the U.S. could read Japanese naval codes, there was no radio traffic to intercept.

Japan set an internal deadline: If negotiations with the U.S. did not go as desired, Pearl Harbor would be attacked. They pushed the deadline to November 29th. Three days later, the Japanese high command sent the message, “Climb Mount Niitaka,” to tell the listening Japanese carrier force to proceed with the attack.

What unfolded in the days to come is the story we’re more familiar with—2,403 Americans were killed,188 U.S. aircraft were destroyed, and the heart of the Pacific Fleet was left sitting on the harbor’s bottom.

Given the nearly 100 years of history between the two nations, Burke said, “We can see why Americans should have anticipated war with the Japanese.” But the specifics of the attack were a surprise. The U.S. knew something was afoot, but anticipated being attacked in the Philippines not Pearl Harbor. The U.S. knew the risks that Japan faced with an attack on Pearl and believed it to be impossible. And the U.S. did not believe that Japan was capable of planning and executing such an attack.

To say that Pearl Harbor was a complete surprise, as most history books do, does not take into account the complex history and relationships between the U.S. and Japan leading up to the attack. The war with Japan was not a surprise, but the location and nature of the first strike was.