On the weekend, the man in the mask came down from the jungle and held a press conference. In the new year, he will travel to Mexico City and address Congress on the need for an Indian bill of rights.

Subcomandante Marcos, voice of the Zapatista National Liberation Army, has been keeping a low profile lately. But he's back, in trademark ski mask, rifle over his shoulder, and pipe hanging from his mouth. Rumour has it he is a university professor who fled to the hills to lead an indigenous uprising in Chiapas, but Marcos has no comment. Showing his face, he jokes, would disappoint his female fans.

It's a mark of the Zapatistas' influence that the very first act by Mexico's new president was to order a partial withdrawal of troops from Chiapas. Vicente Fox also invited the Zapatistas to resume negotiations that broke down under his predecessor. Marcos told reporters he's ready to talk, but not until Mr. Fox completes the troop withdrawal and releases all political prisoners.

It's clear that Mr. Fox sees settling the Zapatista standoff as key to Mexico's stability. Less understood is how powerful the Zapatistas are outside of Mexico—and why. How did this band of indigenous insurgents become symbols (some would say masked mascots) of the international anti-free-trade movement? Why, in the words of a report commissioned by the U.S. military, did the uprising go from being "a war of the flea"—remote and easy to control—to "a war of the swarm"—ubiquitous and impossible to contain?

The answer dates back to Jan. 1, 1994, the day the North American free-trade agreement came into force in Mexico. The Zapatistas chose that day to "declare war" on the Mexican army. A communique placed NAFTA, which banned subsidies to indigenous farm co-operatives, within a long history of colonialism that has impoverished Mexico's native peoples. "Ya Basta!" they said. Enough is enough.

The message was posted on the Internet. Dozens of mirror sites went up, translating and posting regular communiques from the Zapatistas. Caravans of activists hit the road for Chiapas. Groups from Cincinnati to Milan cropped up, calling themselves Ya Basta! And at every demonstration, there were more black masks: Marcos clones, multiplying. Though they were the first rebels to use the Internet, the Zapatistas are less a testament to the power of technology than to the power of language. Marcos's communiques skip lightly from gruesome lists of atrocities to cracks about football games, to Shakespearean verse. He is a master of political metaphor, challenging his supporters to break out of staid old left thinking and build a movement fluid enough to adapt to the global economy.

The Zapatistas' goal is not to seize state control for their ideological camp, but to build an international movement that can rein in corporate power globally and restore community power locally. They call this a movement of "one no and many yeses." Like all indigenous struggles, the Zapatistas are fighting to preserve their heritage. But rather than throwing up blockades and locking out the world, they are inventing a new way to protect their land: opening the doors and inviting the world inside. In 1996, 3,000 activists travelled to Chiapas to attend a gathering "for humanity and against neo-liberalism."

The Zapatistas have taken what could have been a narrow ethnic dispute and made it universal. A Zapatista, Marcos says, is anyone who is fighting for communal space against market forces. And from behind their masks, the Zapatistas have forged a new kind of leadership and heroism, one especially tailored to an age suspicious of both heroes and leaders. Paradoxically, it is leadership without a face, heroes you have to imagine.

This article first appeared in The Globe and Mail.