Operation Popeye: How the U.S. Military Tried to Weaponize Weather 51%
By Darren Orf32%
7/16/2026, 6:00:00 PM
Keywords: Rain, Silver Iodide Crystal, Cloud, Weather, Monsoon Season, Vietnam War, Famous Battle, U S Military, Mud, Operation Popeye, Napoleon, Agincourt
BS Summary: This article contains 23 faulty reasoning types, including Biased Writer Voice, Negativity Bias, and Appeal to Authority, with Anecdotal as the most egregious example at 18.4% saturation with 113 hits. Analysis detected 996 faulty-reasoning hits from 615 analyzed words, generating a BS Score of 51.1% and a BS Rank of 51% (9,404 of 18,913 articles). This article is worse (more manipulative) than 50.30% of the article peer group.
Some of the most famous battles in human history have been decided by the whims of weather.
Heavy rains the night before the Battle of Agincourt in 1415 ensured that mud clung to the armor of French knights (though the English longbow also helped decide that fight).
Poor weather at the Battle of Waterloo in 1815 delayed Napoleon’s troops long enough to provide critical time for the arrival of Prussian reinforcements—and don’t even get us started on Napoleon’s troubles with Russian winters.
Mongols twice attempted the invasion of Japan in the late 13th century, only to be rebuffed by typhoons that the Japanese eventually called “kamikaze,” or divine wind.
Of course, the downside of treating weather as a military asset—especially before the dawn of modern weather forecasting—is that you can’t really know when or where it’ll decide to turn in your favor.
But, as the U.S. military tried to demonstrate during the Vietnam War, you can certainly try.
From 1967 to 1972, the U.S.
Air Force carried out a strange military maneuver that it had never really tried before, and has not been attempted since.
Known as Operation Popeye (or Intermediary-Compatriot during the war itself), the U.S. attempted a secret cloud-seeing project in the hopes of extending the monsoon season plaguing the logistical network of the North Vietnamese military.
Much like soggy soil hindered the French forces at Agincourt centuries before, the goal was to mire this network in mud, making it impossible to resupply North Vietnamese troops.
Carried out by the 4th Weather Reconnaissance Squadron, the common slogan used during those five fateful years was “make mud, not war.”
Supposedly, the effort successfully extended the monsoon season in targeted areas by more than a month.
Cloud seeding was discovered completely by accident in July of 1946, and eventually perfected by Bernard Vonnegut (the older brother of the famous author Kurt Vonnegut).
He pioneered the use of silver iodide crystals, which act as artificial ice nuclei for the formation of clouds.
“The ability of silver iodide to trigger ice formation in clouds cannot be explained solely by its bulk crystal structure,” Jan Balajka, a physicist from TU Wien, explained in a press statement related to a study about silver iodide’s cloud-forming abilities.
“The decisive factor is the atomic-scale rearrangement at the surface.”
The U.S.
Air Force used silver iodine in 50 or so cloud seeding experiments, and found that 82 percent of clouds produced rain following seeding procedures.
But because of overall unpredictability of the factors that determine weather conditions, some of these experiments hit a snag or two.
“We used to go out flying around and looking for a certain cloud formation,” an unnamed official said in an interview to The New York Times in 1972 disclosing this secret operation.
“And we made a lot of mistakes.
Once we dumped seven inches of rain in two hours on one of our Special Forces camps.”
The U.S. isn’t the only nation that has tried similar weather manipulation techniques.
The British government conducted Project Cumulus from 1949 until 1952, but after a deadly flood in the town of Lynmouth, the operation was discontinued.
China also reportedly carried out weather modification experiments to guarantee favorable weather for the 2008 Olympic Games.
On May 19, 1977, 31 nations—including the U.S. and the Soviet Union—signed a U.N. agreement to ban the use of environmental modification in warfare, which was eventually ratified by the U.S.
Senate in 1979.
However, the debate around weather modification, especially in the form of geoengineering, continues to rage as scientists and politicians argue over the best way to avoid the catastrophic effects of global warming.
Analysis
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