https://encyclopedia2.thefreedictionary.com/Operation+Big+City Among the assignments given to Dr. Sidney Gottlieb, head of the secret Project MK-ULTRA, by CIA chief Allen Dulles in 1953 was to perfect a method of producing large-scale aberrant mental states on an unsuspecting population. A substance was sought that the U.S. military could spray over a city when engaging an enemy and render both civilians and military opponents relatively helpless and unable to resist. The substance should be able to “cause illogical thinking” or “produce shock and confusion over extended periods of time” or “produce physical disablement such as paralysis of the legs” or merely “cause mental confusion.”