By Richard V. Acritelli
“…Innocent peoples, innocent nations, are being cruelly sacrificed to a greed for power and supremacy which is devoid of all sense of justice and humane considerations….”
—President Franklin D. Roosevelt, 1937
It was eighty-four years ago this week that America was completely surprised by Japanese attacks against the naval, air, and ground bases at Pearl Harbor, Hawaii. Four years before these actions, Roosevelt delivered the above speech during the height of the Great Depression, warning Americans about the expansionist goals of the Japanese Empire. While the attack on Pearl Harbor killed 2,400 Americans, the tensions that led to the nation’s entry into World War II had been brewing for many years.
During the brutal fighting in Nanking between Chinese forces and the invading Japanese, the USS Panay rescued American citizens from the beleaguered city and escorted three Standard Oil ships. This gunboat operated as a neutral vessel with clear American markings visible from the air. Despite this, Japanese Nakajima fighter planes repeatedly dropped 132-pound bombs on the ship as it struggled to survive. Even as Americans swam to shore, Japanese aircraft continued to strafe sailors and civilians.
Two sailors, an oil tanker captain, and an Italian journalist were killed, and forty people were injured in the assault. Despite the attack, public anger in the United States was limited, as China was distant and Americans were consumed by economic hardship. The Japanese government paid two million dollars in reparations, and for a time the crisis was resolved. Although most Americans opposed entering a foreign war, Roosevelt remained concerned about the nation’s military weakness in the face of growing Japanese aggression. He was also aware of the horrific human rights abuses committed by Japanese forces, including the rape of nearly 80,000 women and the killing of almost 300,000 civilians.
By 1941, Japan—home to 72 million people—had waged a brutal war in China, colonized Korea and Taiwan, and aggressively sought to expand further into Asia. In 1940, the Japanese rejected the influence of Western “imperialists” and established the Greater East Asia Co-Prosperity Sphere to assert regional dominance. Exploiting the global depression and strong American isolationist sentiment, Japan pressed forward with its ambitions. While American CCC workers handed out rakes and shovels, Japan was building a hardened, battle-tested military.
Global powers soon entered a foreign-policy “chess game,” as Germany, Italy, Japan, the Soviet Union, and China formed shifting alliances. By 1940, the United States was deeply concerned about Nazi expansion in Europe—especially after the fall of France—and Japanese dominance in Asia. The Roosevelt administration created the massive Lend-Lease program to provide weapons, food, and funding to the British, Chinese, and later the Soviets. China, however, was fractured by conflict between nationalists and communists, and Japanese control of key regions hindered effective resistance. The Tripartite Pact formally linked Germany, Italy, and Japan in military cooperation. After France was defeated, the collaborationist Vichy government allowed Japan to occupy its Asian colonies in Cambodia, Laos, and Vietnam.
To aid China, Roosevelt ended the sale of military goods to Japan and imposed an embargo on all other products. Japan, dependent on U.S. oil and steel, sought to secure these resources by force from neighboring territories. Roosevelt hoped the embargo would deter further expansion; instead, it accelerated Japanese military planning for an attack on Pearl Harbor.
As Japan threatened Western-held territories in Asia, it also confronted the Soviet Union. Scarred by the earlier Russo-Japanese War yet underestimating Soviet strength, Japanese forces advanced into Manchuria and Mongolia, sparking clashes. Between the mid-1930s and 1941, Soviet and Japanese forces exchanged fire 108 times. Stalin sent weapons to China and ordered Soviet pilots to engage Japanese aircraft. Between 1937 and 1941, Soviet fighters shot down 625 Japanese planes.
The decisive 1939 Battle of Khalkhin Gol, commanded by rising Soviet leader Georgy Zhukov, inflicted 18,000–23,000 casualties on Japan, convincing its leaders not to challenge Soviet power again. Although the Soviets helped partition Poland under the Nazi-Soviet Non-Aggression Pact, Stalin simultaneously signed a neutrality agreement with Japan. Until 1945, this allowed Japan to focus on its imperial aims in Asia. When Germany launched Operation Barbarossa, Japan honored the neutrality treaty and did not attack the Soviet Far East.
Meanwhile, Roosevelt grew increasingly alarmed by Japanese intentions. By 1940, American intelligence had cracked the Japanese PURPLE diplomatic code, allowing officials to read foreign policy messages through the top-secret MAGIC decryption program. The United States did not reveal this capability to other nations until after the war.
However, American intelligence was unable to read Japanese military codes before the attack. After Secretary of State Cordell Hull demanded Japan withdraw from China and French Indochina on November 26, 1941, the Japanese fleet sailed undetected toward Hawaii under strict radio silence. Believing that destroying U.S. aircraft carriers would give them control of the Pacific, Japanese forces prepared their strike. Despite intelligence warnings, poor coordination among senior American commanders left Pearl Harbor vulnerable.
In the early morning hours over Hawaii, swarms of Japanese planes launched a devastating surprise attack—awakening a “Sleeping Giant” and thrusting the United States into World War II.