Operation Popeye

Operation Popeye (Project Controlled Weather Popeye / Motorpool / Intermediary-Compatriot) was a military cloud-seeding project carried out by the U.S. Air Force during the Vietnam War in 1967–1972. The highly classified program attempted to extend the monsoon season over specific areas of the Ho Chi Minh Trail, in order to disrupt North Vietnamese military supplies by softening road surfaces and causing landslides.

The former U.S. Secretary of Defense, Robert S. McNamara, was aware that there might be objections raised by the international scientific community but said in a memo to the president that such objections had not in the past been a basis for prevention of military activities considered to be in the interests of U.S. national security.

The chemical weather modification program was conducted from Thailand over Cambodia, Laos, and Vietnam and allegedly sponsored by Secretary of State Henry Kissinger and the CIA without the authorization of then Secretary of Defense Melvin Laird, who had categorically denied to Congress that a program for modification of the weather for use as a tactical weapon even existed.^[1]