As opponents of corporate rule gather this week in Washington, D.C., vowing to shut down the annual meeting of the World Bank and International Monetary Fund, they will unwittingly reprise a pivotal but nearly unknown moment in radical history.

In May 1971, a staggering 13,000 people were arrested while attempting to shut down the nation's capital through nonviolent direct action, in the last and least remembered major protest against the Vietnam War. The slogan for the Mayday actions explained their rationale: "If the government won't stop the war, the people will stop the government."

It was the largest civil disobedience action ever recorded, bigger than anything carried out by Mahatma Gandhi or Martin Luther King, an uprising so unnerving to the Nixon Administration that it palpably speeded U.S. withdrawal from Vietnam. Yet Mayday has slipped completely from our collective memory, left out of the books and popular accounts that shoehorn protest history into "the Sixties" (and equate the distintegration of the elite Students for a Democratic Society with the end of the New Left).

The Mayday actions are worth rediscovery not only because of the uncanny parallels between what went down in May 1971 and what is planned for April 2000. Mayday is the lost beginning to the radicalism that is now swelling up with such force, the forgotten segue between the centralized, male-dominated leadership of the New Left and the more diverse, radically decentralized direct action movements of today.

"Nobody gives a damn how many dumb sheep can flock to Washington demonstrations, which are dull ceremonies of dissent that won't stop the war," declared one Mayday leaflet circulated before the 1971 protest.

Then as now, many of the most dynamic activists rejected the classic leftist demonstration style -- endless speeches, chants shouted through bullhorns, marshals to keep the crowd in line -- as not just ineffective but boring, as soul-destroying as any assembly line.

In keeping with the desire to create a protest that was "free, joyous, exciting, fun," Mayday promised something that had never been tried before: a major national action organized on a regional decentralized basis. "This means no 'National Organizers.' You do the organizing," explained the elaborate Tactical Manual distributed by the tens of thousands in advance of the event. "This means no 'movement generals' making tactical decisions you have to carry out."

Instead, the initiators of the action detailed twenty-one key targets throughout Washington, D.C., and called on activists around the country to take responsibility for blockading them, by throwing parties in the middle of the street, stalling automobiles at strategic locations, or other creative means. "We had no organization, so we made a virtue out of our weakness, which was what guerrillas had always done," remembers Jerry Coffin, one of the key figures behind Mayday. Demonstrators were encouraged to organize themselves into small "affinity groups," something that had never been tried before in the United States.

Affinity groups will be the building blocks of the "A16" World Bank/IMF actions, and they've become such a routine part of large nonviolent civil disobedience that their origin has been obscured. The concept dates back to the anarchists in the Spanish Civil War, who created grupos de afinidad for reasons of both life-and-death security and anti-authoritarian principle.

The idea first surfaced in U.S. on the most militant reaches of the New Left: among radicals, like the Weatherpeople, who were going underground and structuring themselves into cells; among people who were gravitating away from nonviolence and toward armed struggle. The Motherfuckers, a swaggering group of late 1960s East Village radicals, defined the affinity group as a "street gang with an analysis" which, they said, would evolve into armed cadre during the revolution.

The initiators of the 1971 Mayday protests took this guerrilla form and transplanted it into the arena of nonviolent direct action, where it has evolved up to this day. Mayday -- like the IMF/World Bank protests -- had nonviolence guidelines, which disavowed property destruction as well as harm to living beings. The Mayday Tactical Manual explicitly asked those not willing to abide by these guidelines to stay home.

But it was a different era. The Weather Underground had just set off a bomb inside the U.S. Capitol to support the antiwar cause; nobody was going to get all exercised over a few broken windows. "There was very little talk about sitting down and just being arrested," recalls filmmaker John Scagliotti, who was part of the Gay Mayday grouping within the protest. "It wasn't just bodies that were going to be laid out there, it was going to be vehicles, and things. You were supposed to scope your area and build barricades."

Some people managed to do that. "We threw everything available into the streets," one participant wrote afterwards in the Berkeley Tribe, "garbage cans, parked cars, broken glass, nails, large rocks, and ourselves. To add to the confusion we lifted hoods of cars stopped for lights and let air out of tires."

But most of the protesters were arrested before they could block much of anything. The government mobilized a force of more than 14,000 police and National Guardsmen to sweep the radicals off the streets by the thousands, and herd them into custody at RFK Stadium (promptly renamed "Smash the State Concentration Camp No. 1" by the imprisoned activists).

It was an object lesson in government power, in the huge resources the state can use when it chooses. Rennie Davis, one of the initiators of the Mayday action, called a press conference where he pronounced the protest a failure. "We want to make clear that we failed this morning to stop the U.S. government," he declared. "Our biggest problem was not appreciating the extent to which the government would go to put people on the skids."

But Davis was wrong -- and not only for the classic New Left hubris that led him to present himself as movement spokesman without any movement input. It's a mistake to gauge the success of a no-business-as-usual protest like Mayday -- or A16 -- too literally.

As John Scagliotti observes about Mayday, "What's the whole point of closing down the government anyway? It was a rhetorical, theatrical concept, which most street activism is -- like turtles at the WTO, or AIDS activists putting ashes of dead people on the White House lawn. The power was in the statement that if the government doesn't stop the war, we'll stop the government, and that 13,000 people would be arrested and 30,000 people came down to do this."

There is already much pressure for A16 to live up to some shutdown ideal, to replicate the seamless blockade in Seattle. Sure, the Seattle action actually stopped the World Trade Organization from meeting for several hours, but that was really just the coup de grace: The real victory was in the pressure applied, the publicity garnered, the movement energized.

Mayday is remembered, if at all, as a rout. Yet even former Nixon Administration officials admit it did much to end the Vietnam War. And whatever plays out on the ground in Washington, D.C., this time around, this new movement will change the course of the global economy. The only question is how much.