Speak it aloud, let it ooze over your tongue: how bitter does it taste?

Right now, thousands of Egyptian women who gathered to commemorate the centenary of International Women's Day in the newly liberated Tahrir Square are being assaulted, harassed and brutalised. Not by Mubarak's thugs, but by the men who lately stood beside them as equals on the barricades. As I write, images and reports are coming through on Twitter from women fleeing male aggression in the symbolic heart of what is already being called the Arab Spring. Speak it aloud, let it ooze over your tongue: how bitter does it taste?

"During the revolution, women weren't women -- they were simply Egyptians," writes Egyptian journalist Ethar El-Katatney. "They stood right next to men to liberate their country... women will not -- and cannot -- go back to being silent." It appears, however, that many Egyptian men would prefer their women to do just that -- to shuffle back to their kitchens and stop demanding silly things like social equality and political representation in the new secular constitution of the country they have just reclaimed.

Solidarity has been the watchword of this global resistance movement, but some men seem slow to understand what that word really means. One cannot reserve solidarity for members of one's own gender. The vomitous hypocrisy of turning patriarchal violence against one's comrades in the same space where you fought state violence together just weeks previously should be obvious even to the mobs of men and boys currently chasing women through the streets of Cairo.

The impulse to exclude women from the cultural revolution taking place across the Arab world is clearly a powerful one indeed. The entirety of Egypt fought for democracy, but now its men have turned round and said: not so fast. This revolution was just for the boys.

The liberation of the world from tyranny and destitution cannot precede the gender revolution. On the contrary, the emancipation of women across the globe from the double threat of state violence and male violence ought to be the force that carries the revolution forward, trailing freedom in its wake. The presence of women, and particularly of young women, at the forefront of resistance movements across the world, has been expansively noted -- but how will the world cope when these women demand their rightful place in the bedrooms and boardrooms and circles of power, equal to men on every footing?

How will the world react when the women who liberated their countries demand the right to control their own bodies and their own lives? Today, in Tahrir Square, we're getting a first taste of that reaction, as a joyful celebration of a century of progress for women across the world descends into violence and chaos. And yes, it tastes bitter; even from across the world, from a position of monumental privilege, it burns in the mouth like bitten-back rage.

Human beings liberate themselves by throwing audacity in the face of power. The revolutions in Egypt, Tunisia, Bahrain and Libya have taken the world by surprise, precisely because they demanded the impossible -- the toppling of corrupt and despotic regimes that had clung to power for generations with the backing of western governments -- but some demands are clearly a bridge too far when spoken in women's voices. We can fight the state together, but as soon as we turn around to fight discrimination and domestic violence, the passionate solidarity of men dries up like semen down a trouser leg.

If women had not sacrificed, demonstrated, struck, fought and demanded the impossible for over 100 years, we would still be treated as second-class citizens, denied voting rights and access to health care, considered the property of our male relatives and forcibly married to husbands who could beat, rape and brutalise us as they pleased.

Women and girls still face violence, marginalisation, harassment, political and social exclusion, discrimination and abuse across the world, in their millions, every day, merely because they are female. The first international working women's day, a century ago, recognised that the liberation of women and the liberation of the working class in the Bolshevik revolution and were two halves of the same equation. In Soviet Russia, that lesson was quickly forgotten. A hundred years later, the revolutionaries of Egypt are forgetting it all over again. We cannot let them forget; we must not let anyone forget.

All day I've been justifying why women still need an International Women's Day. I'm sick of having to justify why, while over half the human race still has to swallow daily discrimination and abuse merely on the grounds of gender, we haven't yet sat down and said thank you, sir. Women and workers are not free enough yet to be grateful for how far we have come. We must continue to make demands, impossible audacious demands, and we must never apologise, not even when men try to shout us down, or beat us down, or cut us down.

A century after the first International Working Women's day, we must continue to demand the impossible on behalf of future generations, just as our mothers and grandmothers demanded it for us. History requires no less.