How Imperial Japan turned to the sardine to help build a war machine

Imperial Japan relied heavily on sardine oil, hydrogenated into nitroglycerin for dynamite, as a raw material for its war-oriented chemical industry beginning in the early 20th century. Colonial control of Korea's waters, especially after a 1923 sardine boom off the northern coast, became central to supplying that industry, with Japan's 1931 catch accounting for roughly 44% of the global total.

Korea's Hungnam Complex grew from a fertilizer plant into a self-sufficient facility producing dynamite directly from locally caught fish, shortening supply lines to feed Japan's 1931 invasion of Manchuria and its escalation toward full war in 1937.

The sardine catch collapsed in the early 1940s, constraining Japan's war effort, though the industrial use of sardines for oil, fertilizer and feed continues today.

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