Eve Ensler stands on stage, a tiny figure in the huge arena that is Madison Square Garden, usually home to America's biggest and most masculine sporting triumphs. It is February 2001 and she has just finished a benefit performance of her play The Vagina Monologues. Around her, stacked to the roof, are 18,000 people, mostly women. Taking part that night are Oprah Winfrey, Jane Fonda, Isabella Rossellini and Gloria Steinem.
The Vagina Monologues has run its usual course. Everyone has laughed at the funny anecdotes about trips to the gynaecologist and about what, if your vagina got dressed, it might wear. Most have been shocked at the monologue about female genital mutilation; some cried at the parts about women who have, for many reasons, been shamed. A monologue about a woman from Bosnia who has been raped as an act of war brings about such a sense of pain and desecration that somebody in the audience collapses.
"But haven't we heard it all before?" asks a wizened veteran of the feminist movement. Vaginas, clitoris empowerment workshops, long earnest group sessions involving lying on yoga mats and trying to peer at yourself with a hand mirror. Listened to the lecture, read the article in Cosmo, don't need the bad trip back to the 1970s. And yet, just this month, MPs including Joan Ruddock, Caroline Spelman, Sandra Gidley and Oona King, as well as the Home Office minister Caroline Flint, were performing in Monologues alongside Jerry Hall, before a packed audience at the Criterion Theatre, London, that included Meera Syal and Anita Roddick. It was the third British "V-Day" benefit performance - and this time, even Cherie Blair sent a message of support.
What is different about The Vagina Monologues? Is it the wit of the old lady who went swimming in a vaginal flood with Burt Reynolds? The way it has of creeping inside you with the little girl whose "coochie snorcher" got hurt by a lot of men but then redeemed, in very politically incorrect fashion, by an older woman? Is it the simple joy of the repressed eccentric who came to realise that her vagina was "better than the Grand Canyon"?
Or is it that, at the end of it all, that night in Madison Square Garden, Ensler asks everyone to stand up who has ever been beaten or abused? It's a huge leap of faith, and she knows it. A huge empty space in which the first heads bob up, then more. Then more. Then many. And that's the moment when you understand why The Vagina Monologues is such a phenomenon.
It wasn't always clear that The Vagina Monologues would be a runaway hit. Yet the obscure play performed off-Broadway had women flocking to Ensler's dressing room night after night to share their experiences - often terrible. So many came, in fact, that Ensler founded a movement, "V-Day", on the back of her play, to campaign for an end to violence against women. The campaign, unlikely and unexpected, started to sweep across the world, taking in every country, attracting millions of women, speaking the unspeakable. Banned in China, attacked by various private religious colleges in the United States, but always compelling and wildly popular, the play raised more money to stop violence against women than almost every other project run by women.
Eight years ago, Ensler was 43, a middle-class Jewish woman from suburban Scarsdale, New York, with a bad childhood behind her; a writer who had not found her niche; a political activist who had spent anonymous years chaining herself to railings in support of the usual liberal causes - homeless women, minorities, the poor. Today, Ensler is a heroine of college campuses everywhere, invited to the White House, handed numerous awards, including an honorary degree by her alma mater, Middlebury.
There is something undeniably more emotive in hearing the bad news about violence against women from Ensler, up there on stage - angry and direct - rather than in a dry, soft-spoken presentation from some female junior minister. With Ensler, you feel it's personal. Other groups may have worked tirelessly against the abuse of women in Afghanistan, but it was Ensler's relationship with Rawa (the Revolutionary Association of the Women of Afghanistan) that brought it to public attention. It was V-Day that recently took the leader of an Iraqi women's group to the US to talk about the effect of the war there, and V-Day, with Amnesty International, that organised last month's well-publicised march on Juarez to protest the mass murder of women there. Other films may have been made and articles written, but it was V-Day that pulled off the half-page photo in the Guardian of Jane Fonda defiantly marching for justice in Mexico.
Even though she is often to be found in the midst of world celebrities such as Fonda or Oprah, Ensler always draws your gaze: there is an angry energy there, a determination to make the most of the moment; it is easy to imagine her, young in 1970s New York, all politics, outrage and hustle. But there is also something despairing about her, this woman who once said she had watched the film Looking for Mr Goodbar, in which Diane Keaton struggles with her demons only to end up murdered by a man she picks up in a singles bar, and thought "lucky her", to be out of the misery, and the world.
In The Vagina Monologues Ensler talks without hesitation about being sexually abused as a child, refuses to be labelled by acknowledging that in her life she has been attracted to men and women, and is first to admit to troubled years of drinking and drug-taking in her past. This vulnerable openness, which, together with anger and allure, fills The Vagina Monologues, saves Ensler from being swallowed up in the frenzy of becoming an icon and being turned into a monster.
The question about V-Day as a movement is whether, for all its razzmatazz, it can translate the passion it generates into real political change. It can draw celebrity, but can it draw power?
At a grass-roots level, where V-Day channels most of its funding, it can claim considerable success. Among other achievements, V-Day built a safe house for women fleeing female genital mutilation in Kenya, and supplied the camera to film the Taliban's execution of an Afghan woman - footage now infamous across the world.
On the broader canvas the transition has been more patchy. The "1 per cent campaign" to devote 1 per cent of US defence spending to stopping violence against women has - not surprisingly - found little favour on Capitol Hill, nor has it attracted much wider attention in the US at large. Equally, there has yet to be a woman taking part of whom real political achievement is expected. The line-up at the London event on 8 March was impressive, but would have been more so with an Yvette Cooper, a Beverley Hughes or a Patricia Hewitt. Extracts from The Vagina Monologues were performed by some female MPs at the Labour Party conference in 2002, but it was Eve Ensler's impassioned speech afterwards that captivated the audience.
Without a doubt, it has been Ensler's force of personality that accounts for V-Day's meteoric rise. Does it make sense that a political movement should be based on a play full of fake orgasms and vaginas dressed up in feather boas? No, but Ensler never speaks from her head to ours: rather, she is all heart and passion, past hurt and future hope. To a generation desperate for a respite from managerial politics, this proves an electrifying message. No wonder so many of the women who file into a performance of Monologues sign up to its campaign as they file out.
Warmer and funnier than a Gloria Steinem or a Germaine Greer - and definitely more attractive in every sense than a Betty Friedan or Andrea Dworkin - Eve Ensler speaks to the big picture. It is the longer-term challenge for V-Day to prove that it is both bigger than Ensler, and capable of not living and dying in the light of the celebrities who currently flock to it.