Operation Popeye: When Weather Became a Weapon

During the Vietnam War, the U.S. military launched a highly classified project called Operation Popeye—a secret weather modification program aimed at extending the monsoon season over enemy territories in Southeast Asia.

From 1967 to 1972, U.S. aircraft seeded clouds with silver iodide over parts of Laos, Cambodia, and Vietnam. The goal? Make it rain. Literally. By increasing rainfall, they hoped to flood enemy supply routes like the Ho Chi Minh Trail, bog down troop movement, and disrupt logistics.

The mission's motto? “Make mud, not war.”

The operation remained secret until it was exposed in 1971, sparking outrage and leading to international discussions on weather warfare. In fact, it contributed to the 1977 Environmental Modification Convention (ENMOD), which banned environmental modification techniques for hostile purposes.

Operation Popeye is a fascinating—and unsettling—example of how far military innovation can go when nature itself becomes a tool of war.