Richard J. Evans writes:
Conspiracy theories cluster around violent and unexpected political events. The sudden death of a head of state, the assassination of a government minister, a bomb attack on a building or a crowd: these seemingly random occurrences demand explanation, and for many, the idea that they could be the product of the deranged mind of a single individual seems too simple to be plausible. The authorship must surely have been collective, the planning long-term and meticulous. The killing of John F. Kennedy in Dallas in 1963, or the destruction of the Twin Towers in New York in 2001, are the two major vortices into which conspiracy theorists have been sucked in our own time, generating ever more elaborate explanations and pseudo-explanations. Argument continues to rage, as the proponents of rival theories construct evidential edifices of such staggering detail and complexity that they are often almost impossible for a lay reader to navigate.