When Ann Pettitt, the mother of two young children, and her friends set off in August 25 years ago on a 120-mile trek from Cardiff to the little known American air base at Greenham Common in Berkshire, they gave themselves the ambitious name of “Women for Life on Earth”. Their numbers were tiny but the stakes, they felt, were dauntingly high.

The cold war world was bristling with Soviet and American nuclear weapons, posing the threat of mutual assured destruction (Mad). In a dramatic escalation of the arms race between the superpowers, shiny new cruise missiles were due to be delivered to Greenham, placing Britain’s green and pleasant land in the bull’s eye for targeting by the Soviet Union.

The modest peace march was largely ignored by the media, so on arrival at the base the women decided to borrow the eye-catching tactics of the suffragette movement. They chained themselves to the gates of Greenham and dared the police to remove them. Sympathisers began to turn up bearing makeshift tents, clothing and pots and pans. Many came and went but others stayed. Thus was the women’s peace camp born a quarter of a century ago this month and a new chapter in the history of feminism opened.

“I was motivated by fear and terror,” Pettitt recalled last week. “I was the mother of a two-year-old and a four-year-old and weapons of mass destruction were the ultimate denial of the fact that I’d created life. There was such brinkmanship, I really thought that nuclear weapons might be used.”

Mercifully, they weren’t. President Ronald Reagan once blurted out in front of a live microphone that the bombing of Russia was going to begin in 15 minutes, but it was nothing more than a tasteless joke. In hindsight Reagan’s hardline negotiating stance helped to bring about the collapse of the Soviet Union. By the end of the 1980s the Berlin Wall was down and the velvet revolutions in eastern Europe were under way.

The peace movement lost a foe in Reagan but has gone on to find new friends in today’s Stop the War movement. Women pushing their children in buggies bearing the familiar symbol of the Campaign for Nuclear Disarmament marched last weekend alongside banners proclaiming “We are all Hezbollah now” and Muslim extremists chanting “Oh Jew, the army of Muhammad will return.”

For Linda Grant, the novelist, who says that “feminism” is the one “ism” she has not given up on, it was a shocking sight: “What you’re seeing is an alliance of what used to be the far left with various Muslim groups and that poses real problems. Saturday’s march was not a peace march in the way that the Ban the Bomb marches were. Seeing young and old white women holding Hezbollah placards showed that it’s a very different anti-war movement to Greenham. Part of it feels the wrong side is winning.”

As a supporter of the peace movement in the 1980s, I could never have imagined that many of the same crowd I hung out with then would today be standing shoulder-to-shoulder with militantly anti-feminist Islamic fundamentalist groups, whose views on women make western patriarchy look like a Greenham peace picnic. Nor would I have predicted that today’s feminists would be so indulgent towards Iran, a theocratic nation where it is an act of resistance to show an inch or two of female hair beneath the veil and whose president, Mahmoud Ahmadinejad, is not joking about his murderous intentions towards Israel and the Jews.

On the defining issue of our times, the rise of Islamic extremism, what is left of the sisterhood has almost nothing to say. Instead of “I am woman, hear me roar”, there is a loud silence, punctuated only by remonstrations against Tony Blair and George Bush — “the world’s number one terrorist” as the marchers would have it.

Women are perfectly entitled to oppose the war in Iraq or to feel that Israel is brutally overreacting to Hezbollah’s provocation. But where is the parallel, equally vital debate about how to combat Islamic fundamentalism? And why don’t more peace-loving feminists regard it as a threat? Kira Cochrane, 29, is the new editor of The Guardian women’s page, the bible of the Greenham years, where so many women writers made their names by staking out positions on the peace movement. She has noticed that today’s feminists are inclined to keep quiet about the march of radical Islam. “There’s a great fear of tackling the subject because of cultural relativism. People are scared of being called racist,” Cochrane observes.

Whatever the merits of unilateral nuclear disarmament, women were a lot braver a quarter of a century ago. Pettitt remembers how “we tried to crash the top table at Greenham. You had to be rude to interrupt because you’re never going to be invited to speak”.

I had just left university in the early 1980s when I got swept up in the peace movement. My Saturday afternoons were often spent marching from Hyde Park to Trafalgar Square and on the day when cruise missiles arrived in Britain, I rushed to a protest outside the Houses of Parliament, was arrested by the police, dragged into a black maria van and shoved overnight into a south London police cell. It was nothing compared to what the women of Greenham Common endured, but I felt like a heroine when the next day my male boss at Penguin Books, where I worked as a junior copywriter, paid my fine.

I was a bit sniffy about the all-women’s peace camp because I was partial to men and disliked much of the mumbo-jumbo surrounding it. In her forthcoming memoir, Walking to Greenham (published by Honno), Pettitt writes about the “delightful irony” of liberated women using “emblems of conformist democracy” such as knitting needles and wool to protest against war, but I used to see the ghastly spider webs and children’s mittens tied to the razor wire on the perimeter fence and shudder.