Ancient psycho-chemical use
The use of chemicals to induce altered states of mind dates to antiquity and includes the use of plants such as thornapple (Datura stramonium) that contain combinations of anticholinergic alkaloids. In 184 B.C., Hannibal's army used belladonna plants to induce disorientation.
Use by indigenous peoples
In the 1950s, the CIA investigated LSD as part of its project MK Ultra and some in the US Military speculated about its possible use to disable sentries or incapacitate concentrated masses of troops or enemy populations.  Britain was also investigating the possible weaponization of LSD (lysergic acid diethylamide) and BZ (3-quinuclidinyl benzilate) as nonlethal battlefield drug-weapons. Both the US and Britain concluded that the desired effects of drug weapons were unpredictable under battlefield conditions and gave up experimentation. Reports of drug weapons associated with the Soviet bloc were considered unreliable given the apparent absence of documentation in state archives. Hungarian researcher Lajos Rosza wrote that records of Hungary's State Defense Council meetings from 1962 to 1978 suggest that the Warsaw Pact forum had considered a psychochemical agent such as Methylamphetamine as a possible weapon. The United States eventually weaponized the chemical BZ for delivery in the M43 BZ cluster bomb until stocks were destroyed in 1989.
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