Have you ever wondered why Japan attacked the United States during World War II, despite the U.S. being much stronger? The answer lies in Japan’s involvement in the Second Sino-Japanese War. Japan had modernized its military and expanded its territory, while China, weakened by internal struggles, was unable to resist. In 1931, Japan invaded Manchuria, and over the next few years, they continued their aggressive expansion into Chinese territory.
By 1937, Japan had seized key Chinese cities, but Chinese resistance grew stronger. China launched an attack in Shanghai, hoping to recapture Japanese-held territory. The battle was expected to be brief, but both sides reinforced their positions, leading to a drawn-out conflict. Japan responded by launching a counteroffensive, landing 300,000 troops and pushing the Chinese forces back, eventually capturing the Chinese capital, Nanjing. This victory was followed by the horrific Nanjing Massacre.
Japan’s success in China came with challenges. Despite its military superiority, Japan was a smaller nation with limited resources and struggled to sustain a large army in China. China, expecting Japan to weaken over time, refused to surrender. To deal with this, Japan shifted its focus to crippling China’s economy, targeting its war industries and agriculture. However, Chinese strategies, like flooding the Yellow River, delayed Japan’s advance, though the Japanese continued pushing forward.
In 1938, Japan set its sights on Wuhan, a key industrial hub. Despite being outnumbered, Japan outflanked Chinese defenses and captured the city. This allowed Japan to control much of China’s war production, but the Chinese refused to give up. Japan’s occupation strategy proved costly, and they were still unable to completely defeat Chinese forces, which continued to resist through guerrilla tactics.
As the war dragged on, China began receiving supplies from European-controlled ports, further prolonging the conflict. In 1940, Japan occupied French Indochina to cut off one of these supply routes, which prompted the United States to impose an oil embargo. Japan relied heavily on U.S. oil imports, and without them, its military would soon be paralyzed. The embargo placed Japan in a dire position.
Facing the loss of vital oil supplies, Japan decided to capture oil-rich territories in Southeast Asia. However, this meant going to war with the United States. To delay U.S. intervention, Japan launched a surprise attack on Pearl Harbor in 1941, hoping to secure enough resources before the U.S. could strike back. This decision led to the escalation of World War II in the Pacific.
