The earliest occurrence of the ethnic slur was probably in the Time magazine of 5 January 1942. The American, British, and Australian entry of the Pacific Ocean theatre of World War II heightened the use of racial slurs against the Japanese, such as Jap and Nip. The word Nip became a frequently-used slang word amongst the British Armed Forces. The 1942 Royal Air Force journal made numerous references to the Japanese as Nips, even making puns such as "there's a nip in the air". As part of American wartime propaganda, caricatures and slurs (including Nip) against the Japanese diffused into entertainment, such as exemplified by the Warner Bros.' cartoon Bugs Bunny Nips the Nips (1944). In General Kenney Reports: A Personal History of the Pacific War (1949), George Kenney made racial statements about the Japanese, remarking for example that "Nips are just vermin to be exterminated".
- "Definition of Nip in English". Oxford Dictionaries. Oxford University Press. Retrieved 29 August 2013.
- Savill, Richard (4 October 2006). "Vicar says sorry for 'nip in the air' Japanese joke". The Telegraph.
- Hughes, Geoffrey (2006). An Encyclopedia of Swearing. New York: M.E. Sharpe. p. 261-261. ISBN 978-0-7656-1231-1.
- Casey, Steven (2001). Cautious Crusade: Franklin D. Roosevelt, American Public opinion, and the War Against Nazi Germany. Oxford: Oxford University Press. p. 67. ISBN 0-19-513960-7.
- Bennett, M. Todd (2012). One World, Big Screen: Hollywood, the Allies, and World War II. University of North Carolina Press. p. 102. ISBN 978-0-8078-3574-6.
- Meilinge, Phillip S. (2001). Airmen and Air Theory: A Review of the Sources. Maxwell Air Force Base: Air University Press. p. 38. ISBN 1-58566-101-5.