[8] He then attended a junior college in California, and worked for several technical and vocational schools before making his conspiracy theories known, beginning in 1988. Cooper expanded the speculations of earlier conspiracists by incorporating government involvement with extraterrestrials as a central theme.

[11] According to sociologist Paul Gilroy, Cooper claimed "an elaborate conspiracy theory that encompasses the Kennedy assassination, the doings of the secret world government, the coming ice age, and a variety of other covert activities associated with the Illuminati's declaration of war upon the people of America".

[5] Political scientist Michael Barkun characterized it as "among the most complex superconspiracy theories", and also among the most influential due to its popularity in militia circles as well as mainstream bookstores.

[6] Historian Nicholas Goodrick-Clarke described the book as a "chaotic farrago of conspiracy myths interspersed with reprints of executive laws, official papers, reports and other extraneous materials designed to show the looming prospect of a world government imposed on the American people against their wishes and in flagrant contempt of the Constitution.

"[12] Cooper gained attention in Ufology circles in 1988 when he claimed to have seen secret documents while in the Navy describing governmental dealings with extraterrestrials, a topic on which he expounded in Behold a Pale Horse.

[15] Lear was the author of a post titled "The UFO Coverup" which incorporated elements of mythos from Paul Bennewitz, a ufologist who was later revealed to have been fed disinformation by American counter-intelligence agent Richard C.

[8] In 2018, columnist Colin Dickey noted the pair's influence, writing "in the early years [UFO writers] did not, by and large, embrace strong political positions.

He accused President Dwight D. Eisenhower of negotiating a treaty with extraterrestrials in 1954, which supposedly allowed the aliens to abduct humans in exchange for technological assistance.

[23] Cooper's video purporting to prove his theory was analyzed by several television stations, according to one source, and was found to be "... a poor-quality fake using chunks of the... Zapruder film.

[24] From 1992 until his death in November 2001, Cooper originated his radio show, The Hour of the Time from a studio in his house at the top of a hill in the small White Mountains town of Eagar, Arizona, 15 miles from the New Mexico border.

[22] As Cooper moved away from the Ufology community and toward the militia and anti-government subculture in the late 1990s, he became convinced that he was being personally targeted by President Bill Clinton and the Internal Revenue Service.

[6] On November 5, 2001, Apache County sheriff's deputies attempted to arrest Cooper at his Eagar, Arizona home on charges of aggravated assault with a deadly weapon and endangerment stemming from disputes with local residents.

Federal authorities reported that Cooper had spent years evading execution of the 1998 arrest warrant, and according to a spokesman for the Marshals Service, he vowed that "he would not be taken alive".