In January 1996, I was one of 10 women who carried out a Ploughshares action in England, disarming a Hawk attack aircraft at a British Aerospace factory in Lancashire. The Hawk was about to be delivered to the Indonesian military, for use against civilians in illegally occupied East Timor. The action – the Seeds of Hope East Timor Ploughshares – came after three years of campaigning to stop the sale by other means. Together with thousands of people all over the country, I had written letters, signed petitions, taken part in public meetings, rallies and marches and organized acts of civil disobedience.

Nothing had worked, and the planes were about to be delivered. The only thing left to do was to disarm them ourselves.

After our act of disarmament, we were arrested and charged with criminal damage – at that point put at the equivalent of $3.6 million. We were refused bail and held in prison for six months. In British law, you are allowed to use reasonable force to prevent crime: We argued that we had been using reasonable force to prevent the crime of genocide in East Timor. The jury listened carefully to the evidence about East Timor and how selling Hawks to Indonesia made Britain complicit in the genocide, and acquitted us of all charges.

The acquittal was a landmark in peace movement history: It was the 56th Ploughshares action worldwide, but the first time that anyone had been found not guilty. The jury’s verdict showed that ordinary people, when presented with the facts, can see that extraordinary action is justified when one’s government is engaged in criminal behavior.

To mark the 20th anniversary, I’m writing a book that tells the inside story of the action. Seeds of Hope happened when the Internet was in its infancy, and there’s very little written about it. “The Hammer Blow” — to be published by Peace News Press, which is running a crowdfunding campaign until October 28 — will tell the full story from my point of view, including the year-long preparation, the action itself, the vital role of the support group, the prison time, trial and acquittal.

Although the Seeds of Hope action took place almost two decades ago, it is still relevant today. Britain is the world’s second largest weapons dealer, selling arms to countries embroiled in conflicts and guilty of terrible human rights abuses. As refugees pour out of war zones in the Middle East, Britain’s response is to offer sanctuary to a very few, while continuing to see that area of the world as a key market for arms deals.

Campaigners in every area — the arms trade, the environment, human rights — need to be prepared to stand up and hold governments to account. The Seeds of Hope action showed how a small group of committed women did just that. “The Hammer Blow” aims to inspire new generations of activists, and to show that, even when the cards appear stacked against us, we can still win. What follows is an excerpt of the book.

For several weeks I had been having panic attacks. They would swoop on me out of nowhere; walking down the street, not even thinking about the action, my legs would suddenly turn to jelly, my heart would start pounding and great waves of panic would engulf me. I’d have to sit down and take some deep breaths to calm myself. These episodes made me worried about how I would cope on the night: If I could react like that beforehand, how much worse would it be in the actual event?

But now, to my surprise, I felt very calm and focused. We’d spent nearly a year in planning, and had talked through every last detail of what we were to do, right down to the configuration in which we’d cut the fence and who would wield each tool as we broke into the hangar. I think we all needed reassurance that we could carry off this disarmament, and such detailed planning gave us a sense of security; there were to be, we hoped, no surprises.

We finished the minute’s silence, gave each other a last hug, and headed for the fence. Lotta and I were carrying boltcutters, Jo had the Japanese peace cranes we’d made to tie on the fence as a symbol of our peaceful intentions.

Lotta and I worked on cutting an arch-shaped hole in the fence, while Jo tied the peace cranes nearby, her frozen fingers struggling with the string. We were confident the fence wasn’t alarmed: Jo and I had made a small cut in it during one of our night time recces some weeks earlier, before giving it a vigorous shake and scuttling behind a bush to watch for any reaction. Nothing had happened.

After the trial, a British Aerospace worker in a more unguarded moment told us that there was in fact a movement sensor on the site but it was set off so often by rabbits that it was generally ignored. Perhaps that night the security guards had been sitting in their office wondering vaguely about the three extremely large rabbits hopping around.

It seemed to take ages to cut the fence; our hands were cold and we were made clumsy by the urgency of the situation. Finally the last strand gave way. I scrambled through the hole and grabbed the bags which Lotta and Jo passed to me before squeezing through themselves.

From where we had entered, it was only about 50 yards to the nearest entrance, a fire door on the corner of the building. But to reach it we had to walk through chest-high grass, which was dry and frozen, and crunched and snapped as we passed. There was otherwise complete silence apart from the occasional distant engine, and the noise of the grass seemed incredibly loud. But nobody seemed to hear us, and soon we were clambering up the bank onto the road around the hangar.

The fire door was right in front of us. We planned to smash the glass, then reach through and push the exit bar from the inside. Having no idea how strong the glass would be, we’d taken no chances and come equipped (“armed” as the prosecutor would later put it with no sense of irony) with an enormously heavy iron bar, a weight from inside a sash window. It had been ceremoniously presented to us a few weeks earlier by Ricarda and Rowan, support group friends who were replacing their windows. Not wanting it to appear to be an offensive weapon, they had carefully painted “Women disarming for life and justice” on it. It would later be brought out in court as evidence against us, the prosecutor grimacing slightly as he struggled to hold the huge lump of iron whilst reading the words to the jury.

There was a camera over the fire door, and security lights on each corner of the hangar. Standing there in the glare of the lights I felt very exposed and vulnerable. Surely they must have noticed us? What if we were caught now?

We’d talked a great deal about what we could do to make the action a success even if we didn’t manage to disarm the Hawks. To that end, we carried with us personal statements and a video we had made to leave at the site to explain what we had come to do. We even had business cards with our names and “Seeds of Hope East Timor Ploughshares” inscribed on them. Nobody would be left in any doubt as to what our intentions were.

But despite all that, I knew that I’d be desperately disappointed if we failed to hammer on the planes. And more than any personal feelings, the fact was that we were trying to prevent these Hawks from leaving for Indonesia; it was absolutely vital that we were able to carry out the action as planned.

The glass smashed easily, and Lotta put her hand through the window, feeling about for the bar inside. “I can’t find it,” she whispered. “Can you break the other panel?” I smashed the other panel of glass. “I still can’t feel it,” she said, her voice tense. “Let’s try the crowbars!”

In desperation, and expecting a heavy hand on our shoulders at any minute, we set to with the crowbars, but the gap between the two doors was too thin for them. Things weren’t looking good: It would be terrible to be caught now, so near and yet so far from our target.

While Lotta and I wrestled with the door, Jo ran off round the corner to see if we could get in anywhere else. A couple of minutes later she was back. “I’ve found a way in,” she said.

There were small doors set into the big folding metal shutters which opened to let the planes in and out of the hangar, but in our planning we’d dismissed these as being too difficult to crack. However, Jo had almost got one open with her crowbar; a little extra pressure from Lotta and me, and the whole lock popped off. We were in.

Several hours later, we were being interviewed by detectives at Lytham police station. They were very keen to know how we’d got into what they’d obviously been told was a very high security area without being detected. “Come on, just tell us, it won’t do your case any harm,” they coaxed.

I was tempted to tell them how easy it had been, how we’d more or less just walked right in, but I bit my tongue and smiled at them in what I hoped was a suitably enigmatic manner. They thought we’d had inside information or help; how else could three women have got into such a fortress? In fact, all the information we had was publicly available — at least to anyone willing to spend many days and nights sitting in freezing ditches peering through binoculars — and the lack of security was simply luck.

The lights in the hangar were on low, bathing all the planes inside in an eerie green light. We were interested in only one of them: an Indonesian Hawk. By the time of the action, Jo and I were experts on how to identify Hawks. We’d spent hours browsing military aircraft magazines and planespotters’ guides. We knew how to tell a Hawk 60 from a Hawk 100 and a Hawk 100 from a Hawk 200. We knew which serial numbers had been allocated to the Indonesian order of 24 Hawks. British Aerospace were also making the planes for other countries, including Saudi Arabia, and while that regime committed plenty of its own human rights’ abuses, we needed to keep the issue very clear, and not hammer on the wrong planes.

But there, standing right in front of us, was the apple green Hawk ground attack plane that Jo and I had seen being taken out of the hangar two days earlier. The lettering on its tail — ZH 955 — told us that it was destined for the Indonesian military, one of the world’s most brutal regimes. This was one of the actual weapons they planned to use to perpetrate murder in East Timor.

I’d expected it to be much bigger. For so long it had loomed large in my imagination, filling my thoughts, screaming into my dreams, overwhelming me with its power and violence. And yet now that we were standing in front of it, the Hawk seemed so small, so vulnerable — so easy to disarm.

By this time we’d been inside the site for about 10 minutes. We’d cut through a fence, smashed two panes of glass, and forced a door, all under the eye of security cameras. Discovery must be imminent: We had to work fast.

I had a heavy lump hammer that I’d bought a few months earlier to chip mortar off old bricks when I was rebuilding a wall. I’d decorated it with the words from the biblical book of Isaiah that have inspired so many disarmament actions: “They shall beat their swords into ploughshares and their spears into pruning hooks.” On the handle I’d painted “Choose life!” a reference to another biblical line, from Deuteronomy: “I put before you life and death, blessing and curse. Therefore, choose life.” For me, this action was all about choosing life: Choosing to say yes to a disarmed world and no to weapons of destruction; to say yes to nonviolence and no to violence; to say yes to accountability for our actions and no to the abdication of responsibility shown by British Aerospace and the British government.

Jo had a smaller hammer, which had been a gift from friends, and Lotta had two hammers, which had both been used in previous Ploughshares actions. One of the beautiful things about Ploughshares actions is that anyone can do them. You don’t need to be a technical genius or an engineer; you don’t need to be physically strong; you don’t need any expensive equipment or special skills. All you need is a hammer and a functioning arm. We each had both of those things. We started hammering.