Toward the end of the latest Star Trek film, Captain James T. Kirk makes yet another in a string of bold decisions: He decides he will join forces with one of his enemies to fight another even more dangerous enemy, rationalizing his decision with the axiom that “the enemy of my enemy is friend.” Spock, as ever, is more skeptical, and warns Kirk that this saying was an Arab proverb coined by a prince who was soon decapitated by his “friend.” It’s one of the movie’s better laugh lines—but is it right? Or has Spock’s Vulcan memory somehow failed him?
This statement must have been made by his human half. The decades-spanning, cross-cultural history of the proverb is a little murky, but, unless our understanding of history changes between now and the year 2259, Spock’s story appears to have no basis in historical fact: The adage doesn’t appear to have originated with an Arab, nor a prince, nor a man who lost his head.
It’s true that the phrase is commonly described as an Arab proverb. Longtime New York Times language columnist William Safire learned this when he asked around about the phrase in 1990, in the buildup to the first Iraq War: “Everybody I ask about this says, ‘It’s an old Arab proverb,’ ” he wrote. And a similar expression does exist in Arabic: Safire cited the New York Times’ correspondent in the Middle East, Tom Friedman—later to become a columnist for the paper—who told him of a similar saying he had heard in that part of the world: “Me and my brother against my cousin; me, my brother and my cousin against the outsider.”
But when I asked various experts who study the origins of words and phrases, none could support Spock’s assertion. Instead, they referred to the history provided by the Yale Book of Quotations, which suggests that the phrase is the summary of advice given not by an Arab but by Kautilya, the “Indian Machiavelli.” In the Arthashastra, a foundational text of military strategy written in Sanskrit around the 4th century B.C., Kautilya puts it this way: “A king whose territory has a common boundary with that of an antagonist is an ally.” (Or, as his theory is commonly summarized: “Every neighboring state is an enemy and the enemy’s enemy is a friend.”) After his death—whose circumstances are a little mysterious but don’t seem to involve beheading—Kautilya’s counsels remained influential around much of the world for centuries.
In the West, the proverb eventually found a more recognizable form in Latin. Amicus meus, inimicus inimici mei (“my friend, the enemy of my enemy”) was a common saying by the early 18th century, when it appeared in books otherwise written in Italian (by 1711), written in German (by 1721), and translated into Spanish (by 1723).
From there, the axiom may have entered English through French. As Garson O’Toole, the self-styled Quote Investigator, pointed out to me, the expression “every enemy’s enemy is a friend” was described as a “popular” line of reasoning in an 1825 English translation of a French book, History of the Conquest of England by the Normans. The adage took on the more familiar English phrasing, “the enemy of my enemy is my friend,” by the late 19th century. The first recorded instance for this phrasing comes from Gabriel Manigault, who in his 1884 Political Creed described the sense that “the enemy of my enemy is my friend” as a “natural feeling.”
Natural or not, the phrase didn’t appear in the New York Times until 1954—where it was described, not for the last time, as an “ancient Arab saying”—and only became a common household saying during the many decades of the Cold War.
Thanks also to Barry Popik, Ben Zimmer of the Visual Thesaurus and Vocabulary.com, and Fred Shapiro, editor of the Yale Book of Quotations.