George Donald King McCormick (11 December 1911 – 2 January 1998) was a British journalist and popular historian, who also wrote under the pseudonym Richard Deacon.
In his prolific output as a historian, McCormick was attracted to controversial topics on which verifiable evidence was scarce.
He wrote histories of the Russian, Chinese, Japanese, British, and Israeli secret services, and biographies of Sir Maurice Oldfield and Ian Fleming.
(The equally controversial Rupert Allason, who once worked for McCormick, has continued to press this particular claim after Peierls's death.)
An assessment by a number of academics and specialists of what has been termed McCormick's "fraudulent career", which includes evidence supplied by his personal papers, was published (2015) as the third volume of a biography of economist Friedrich Hayek.