A “fifth column” is a group which operates in secret, usually within enemy lines, in order to help further a cause which they secretly support.
The term originated with Emilio Mola Vidal, a Nationalist general who served under Franco during the Spanish Civil War. As Mola Vidal was marching on Madrid with four columns of his own army, he announced that he also had a “fifth column” of supporters who were working to help him from within the capital.
Classically, a fifth column works by infiltrating a nation, introducing its supporters into positions of trust, and gradually influencing public policy and military issues. Fifth column workers can also influence the people of a nation by spreading rumors and fear.
However, the notion of the “fifth column” can also be used to create fear and distrust among the people of a nation. In the aftermath of the September 11 attacks, for example, the New York Post warned darkly that there was a “fifth column” operating in the United States and working to bring down the country:
The FBI is looking for hundreds of men inside the United States suspected of playing a role in Osama bin Laden’s terror network. The support network that made last week’s attacks possible is right here, burrowed inside Arab and Muslim communities in American neighborhoods. For the first time in American history, we have irrefutable evidence that there is a dangerous and functional foreign-born “fifth column” at work on American soil.
The Post was hardly the first to issue warnings about a fifth column operating in the United States. Decades earlier, Franklin Delano Roosevelt warned that there was a “fifth column” of Nazi sympathizers working within the United States where, he said, they were plotting to carry out espionage and sabotage.
In modern times, some on the left have been warning that the Russian president, Vladimir Putin, is setting up a “fifth column” throughout Europe:
Putin…has formed an alliance with many European far-right political parties and their leaders, who have delivered consistent adherence to Russian interests even when it contradicts some of their past positions…These far-right parties are capitalizing on economic and security crises in Europe to build popular support and now operate as a fifth column that is undermining the Western liberal order from within. President Donald Trump’s unwavering support for Putin and his pursuit of policies that advance Russia’s goals show disturbing similarities to the European far right that are equally difficult to rationalize.”
It’s worth noting that the Cato Institute has argued that the true danger of the fifth column isn’t the danger posed by the saboteurs and secret agents – it’s the fear which they cause among the general population. In Spain, for example,
“The city [Madrid] never fell to the nationalists, but fear of this “fifth column” caused the Republican government under Francisco Caballero to abandon Madrid for Valencia and it led to a massacre of nationalist prisoners in Madrid during the ensuing battle. So a “fifth column” is not so much an insidious group of spies or traitors as it is the threat of such a group which causes the incumbent power to miscalculate and overreact.”