Make Mud, Not War: Operation Popeye’s Weather Weapon

During the Vietnam War, U.S. aircraft seeded clouds to make it rain—on purpose. The goal? Turn roads into mud and war zones into swamps.

This episode of Unsettled: The Hidden Record uncovers Operation Popeye, a secret military weather modification program launched by the U.S. Air Force in the late 1960s. By dispersing silver iodide into storm systems over Southeast Asia, American planes extended the monsoon season in order to hinder enemy movement along the Ho Chi Minh Trail.

The operation was classified for years. Even Congress didn’t know. When it came to light, it sparked an international treaty banning environmental warfare—but by then, it had already been used.

How far was the U.S. willing to go to shape the battlefield? And how much control do we really have over nature?