theme \ kən-'spir-ə-sē 'thē-ə-rē \
: a belief that some covert but influential organization is responsible for a circumstance or event
From medieval times until the present day, conspiracy theories have spread antisemitic beliefs that blame Jews for the world’s worst tragedies. Jews were accused of poisoning wells in 14th century Europe causing the Black Death and in 21st century America, they were charged with being the "hidden hand" responsible for the 9/11 terrorist attacks (see poisoning the well). With the onset of COVID-19, Jews were accused of both spreading the virus and profiteering off of the vaccine.
Antisemitism, like all conspiracy theories, is irrational in nature— unable to be explained by logic or sound reasoning. In his 1986 book Antisemitism in the Contemporary World, Michael Curtis describes how no other group aside from Jews has been blamed simultaneously for opposing phenomena: being an insular yet cosmopolitan group; for being capitalists and behind Communist revolutions; for being subhuman but also a chosen people. To conspiracists, conspiracy theories are “self-sealing,” meaning any attempt to dispel the theory with logic will serve as evidence to the conspiracist of the theory’s existence.
Many conspiracy theories are rooted in the antisemitic myth that Jews are the “hidden hand,” plotting to take over and control the world (see control, puppet master). These conspiracies of control and manipulation were spread through the fictitious publication The Protocols of the Elders of Zion and are still present today.
Other conspiracies allege Jews are behind their own hate crimes, such as the “false flag” theories, and even go as far as to say the Holocaust was a hoax created by Jews to gain sympathy (see Holocaust denial, Holohoax).