Bretnor's father, Grigory Kahn, was a Russian Jew, but he and his family left Siberia for Japan in 1917 and later settled in the United States.
He was hired by the Office of War Information to write propaganda to be sent to Japan, and papers related to his work are held in the SOHS Archives.
After World War II, Bretnor worked for the U.S. State Department until ill health once again caused him to resign.
[2] Under the pseudonym Grendel Briarton (an anagram of Reginald Bretnor), he published a series of over eighty science-fiction themed shaggy-dog vignettes featuring the time-traveling hero Ferdinand Feghoot.
In one example, he explained his inability to pay his dues for a Sherlock Holmes fan society by turning out his empty pockets and declaring "share lack".
Largely unnoticed by his science fiction readership but hinted at by his Future at War series, it proved him a scholar of varied talents.