In military terms, "FAFO" is an acronym that stands for "F*** Around and Find Out" (sometimes softened to "Fool Around and Find Out"). It is used as a warning that careless, provocative, or foolish behavior—especially from enemies—will lead to serious and often harsh consequences. The term has been popularized recently by Secretary of War Pete Hegseth in a military context, where it was used to signal a tough and uncompromising stance toward adversaries, emphasizing that any challenge to the U.S. military will be met with decisive and severe response.
"FAFO" functions as a blunt message of deterrence, implying that any actor who "messes around" will "find out" the consequences of their actions, especially in a military or conflict setting.
