n. (context politics business military espionage English) The organization of clandestine activity in such a way that knowledge of its existence may be deny by those in authority.
Plausible deniability is the ability for persons (typically senior officials in a formal or informal chain of command) to deny knowledge of or responsibility for any damnable actions committed by others (usually subordinates in an organizational hierarchy) because of a lack of evidence that can confirm their participation, even if they were personally involved in or at least willfully ignorant of the actions. In the case that illegal or otherwise disreputable and unpopular activities become public, high-ranking officials may deny any awareness of such act in order to insulate themselves and shift blame onto the agents who carried out the acts, confident that their doubters will be unable to prove otherwise. The lack of evidence to the contrary ostensibly makes the denial plausible, that is, credible, although sometimes it merely makes it unactionable. The term typically implies forethought, such as intentionally setting up the conditions to plausibly avoid responsibility for one's (future) actions or knowledge. In some organizations, legal doctrines such as command responsibility exist to hold major parties responsible for the actions of subordinates involved in heinous acts and nullify any legal protection that their denial of involvement would carry.
In politics and espionage, deniability refers to the ability of a powerful player or intelligence agency to pass the buck and avoid blowback by secretly arranging for an action to be taken on their behalf by a third party ostensibly unconnected with the major player. In political campaigns, plausible deniability enables candidates to stay clean and denounce third-party advertisements that use unethical approaches or potentially libellous innuendo.
In the US, plausible deniability is also a legal concept. It refers to lack of evidence proving an allegation. Standards of proof vary in civil and criminal cases. In civil cases, the standard of proof is "preponderance of the evidence" whereas in a criminal matter, the standard is "beyond a reasonable doubt." If an opponent cannot provide evidence for his allegation, one can plausibly deny the allegation even though it may be true.
Although plausible deniability has existed throughout history, that name for it was coined by the CIA in the early 1960s to describe the withholding of information from senior officials in order to protect them from repercussions in the event that illegal or unpopular activities by the CIA became public knowledge. The roots of the name go back to Harry Truman's national security council paper 10/2 of June 18, 1948, which defined "covert operations" as "...all activities conducted pursuant to this directive which are so planned and executed that any U.S. Government responsibility for them is not evident to unauthorized persons and that if uncovered the U.S. Government can plausibly disclaim any responsibility for them." [NSC 5412 was de-classified in 1977, and is located at the National Archives, RG 273.]
Usage examples of "plausible deniability".
And if she never told anyone, the government would at least have plausible deniability.
What if plausible deniability and bureaucratic confusion aren't the reasons the president was misled?
As a result, they try to follow policies of plausible deniability, which means that messages are given to the CIA to do things but without a paper trail, without a record.
You've got your plausible deniability, and in court I'll testify that you didn't help us, even though you did.
Perhaps they were employing the useful CIA invention of 'plausible deniability'.