WASHINGTON—A group of women have started a sex strike in Pereira, a city in western Colombia, to persuade their men to give up violence. They will make love again only when their husbands and boyfriends make peace. A catchy song put together by the women is blasting out of all the local radio stations to persuade other females to send their partners to the sofa.

The Greek playwright Aristophanes, who 2,500 years ago invented the concept of the sex strike to achieve peace, must be celebrating somewhere in the afterlife. In “Lysistrata,” a group of women who are sick of so much death and destruction, try to force their men to put an end to the Peloponnesian War by declaring their bodies off-limits.

It is not the first time real life has honored Aristophanes. The sex strike was tried in Colombia itself in the late 1990s at the behest of an army chief. And in a Turkish town, some women used the same tactics to force their lazy partners to restore the water supply. Success ultimately eluded the strikers both times, but some short-term results were achieved.

In the current case, the move was preceded by some interesting research. In a city that is considered the most violent in Colombia and where nine out of 10 victims are between the ages of 14 and 25, violent men apparently consider sex more enjoyable than snuffing their neighbors. Many of them partake in the gang culture because they think it makes them sexually attractive. More significantly, a number of women thought so too—until it dawned on them that they held to key to the peace.

Julio Cesar Gomez, the security official at Pereira’s local government, says, “this is about changing the cultural parameters: Some women thought that men wearing fatigues and holding guns looked more attractive, and most men are members of gangs not because of financial necessity but because killing is associated with power and sexual seduction.‘’

Why is this story so seductive? Because it involves the greatest lesson in the time of terrorism: The ultimate hope for halting indiscriminate violence lies in civil society. Unless there is a grass-roots effort to uproot violence, terror cannot be stopped. It will merely be replaced by another type of terror.

In fact, that is an old and universal lesson. In the 1990s, thousands of Peruvian peasants successfully confronted Shining Path terrorists. In the 1960s, Venezuelans put out the flames of Castro-inspired guerrillas thanks to the mobilization of the population in neighborhoods rich and poor. In Italy, where the success against the Red Brigades is often simplistically attributed to the ruthless special courts, it was civil society—particularly the unions, the very “proletarians” in whose name that organization killed and maimed—that denied the terrorists the oxygen necessary to sustain their efforts. In Spain, the civic association formed by terrorism’s victims has played a part in forcing the Basque separatist group ETA to make some concessions. By contrast, in those countries where civil society failed to mobilize, or the brutal way in which authorities responded to terrorism alienated ordinary citizens, the price of victory was tyranny. Argentina in the 1970s is a case in point.

We hear, from time to time, about the success achieved by President Alvaro Uribe in reducing Colombia’s violence. There is no denying that success. Political murders and kidnappings—to cite but one statistic—have dropped by more than 80 percent. When analysts acknowledge this achievement, they tend to mention that Uribe has doubled the defense budget and expanded the police force by 25 percent. But they fail to point out that in the new millennium, Colombians—who for years seemed etherized by fear—rose up to the challenge in their neighborhoods, the workplace, the countryside. This quiet, grass-roots heroism is more difficult to detect than military budgets, so analysts often fail to look beyond the obvious.

According to the Office of the U.N. High Commissioner for Refugees, half the internally displaced persons in Colombia are women and 40 percent of the displaced families are headed by females, compared to 28 percent in the case of non-displaced families. The brave girls of Pereira show us that ultimately the fight against violent gangs who hit and run and then hide among the population is not so much a matter for governments as for civil society. Rather than wait passively for others to resolve their problem, they have decided to fight back with Greek literature and (no) sex. Chapeau!