Disinformation is the deliberate dissemination of false information. It may include the distribution of forged documents, manuscripts, and photographs, or propagation of malicious rumors and fabricated intelligence.
In the context of espionage or military intelligence, it is the deliberate spreading of false information to mislead an enemy as to one's position or course of action.
In the context of politics, it is the deliberate attempt to deflect voter support of an opponent, disseminating false statements of innuendo based on the candidates vulnerabilities as revealed by opposition research. In both cases, it also includes the distortion of true information in such a way as to render it useless.
Disinformation should not be confused with misinformation, which is merely false information spread by mistake.
Disinformation techniques may also be found in commerce and government, used by one group to try to undermine the position of a competitor. It in fact is the act of deception and blatant false statements to convince someone of an untruth. Cooking-the-books might be considered a disinformation strategy that led to the Sarbanes-Oxley Act.
Unlike traditional propaganda and Big Lie techniques designed to engage emotional support, disinformation is designed to manipulate the audience at the rational level by either discrediting conflicting information or supporting false conclusions.
Another technique of concealing facts, or censorship, is also used if the group can affect such control. When channels of information cannot be completely closed, they can be rendered useless by filling them with disinformation, effectively lowering their signal-to-noise ratio and discrediting the opposition by association with a lot of easily-disproved false claims.
A common disinformation tactic is to mix some truth and observation with false conclusions and lies, or to reveal part of the truth while presenting it as the whole (a limited hangout).
A classic example of disinformation was during the World War II, preceding the D-Day landings, in what would be known as Operation Fortitude. British intelligence convinced the German Armed Forces that a much larger invasion force was about to cross the English Channel from Kent, England. In reality, the Normandy landings were the main attempt at establishing a beachhead, made easier by the German Command's reluctance to commit its armies.
In 1957 The CIA knew about the Mayak accident but the information was not released publicly because of the "reluctance of the CIA to highlight a nuclear accident in the USSR, that could cause concern among people living near nuclear facilities in the USA".
In 1986, national security adviser John Poindexter wrote for President Ronald Reagan a "disinformation program" aimed at destabilizing Libya's Colonel Muammar al-Gaddafi by planting reports in the foreign press about an impending conflict between the two countries. However, the false information eventually reached The Wall Street Journal—a phenomenon known in the trade as blowback .
A few additional examples of alleged Soviet disinformation against the United States included the following :
Former Mossad case worker Victor Ostrovsky claims that the Israeli secret service successfully used disinformation techniques to cause the US to blame Libya for the 1986 bombing of La Belle Discothèque in West Berlin.