AS peace activists go, Alastair McIntosh has quite a lot of time for the military. It’s a paradoxical respect born of close contact and free exchange of views; he is finding, somewhat to his own surprise, more and more common ground with senior officers and strategists. Politicians are another matter. For the past five or six years McIntosh, an author, campaigner, academic and Quaker pacifist, has addressed 400 top brass at the Joint Services Command and Staff College – Britain’s foremost school of war – at Shrivenham near London. He has not been haranguing them through a megaphone across barbed wire, though that would not be his style anyway. No, McIntosh speaks as an invited guest with direct access to the lion’s den. A respected campaigner on non-violence and environmental issues, he is there “to make us think”, according to the course director. It seems to be working.

“I’m finding that some of the most exciting thinking about alternatives to war is coming out of military people themselves,” McIntosh says at his home in Kinghorn, Fife. “For one thing, they’re actually adopting the language of the peace movement, expressions like the ‘spiral of violence’ and so on. Lecturing at the college and elsewhere has taught me that many in the military have thought far more deeply about war than most people have. Many of them have seen it face to face, of course, and know how horrific it is.”

He shows me an e-mail from a lieutenant-colonel in the US army, who jokes about getting a war games exercise over and done with as quickly as possible to leave more time for golf. Then the officer makes a serious philosophical point about perceptions of “them” versus “us”. McIntosh laughs at the Pentagon disclaimer at the end that the e-mail is not necessarily virus free. “Ha! They can drop atom bombs but they can’t guarantee their e-mails are clean.”

McIntosh, a fellow of Edinburgh’s Centre for Human Ecology, spent much of the last year adding his efforts to the ultimately unsuccessful campaign to prevent the bombing and invasion of Iraq. He has been both dismayed and encouraged by some of the aftershocks. “One of the consequences is that it’s making a lot of people think very hard about alternatives. But it was strange; in the lead-up to it, I had very senior military people saying to me, ‘Why aren’t you people being more successful in stopping the politicians? Because we’re not comfortable with what we’re being pushed towards.’

“And it’s been made clear to me since, by people right up in the chain of command, that many of them are profoundly unhappy with what the politicians have asked them to do in this war. They fear they have been made to do something that is possibly illegal. They take very seriously the possibility that they might be war criminals. This is where Tony Blair and Alastair Campbell and Jack Straw have been so corrupt.

“So I don’t think there’s a black and white distinction between the military and the peace movement. There’s a sense in which we are both working for peace. The very important distinction is that, whereas we are all prepared to die for our beliefs, those of us committed to non-violence are not prepared to kill. That’s the only absolute I try to hold on to. I say try, because were you to jump on me and suddenly attempt to stick a knife into me, I can’t honestly say what my instinctual responses would be. What I can say is that it means you don’t prepare to fight.”

McIntosh, who is 47 and grew up on Lewis, gives two examples of the power of non-violence from his own experience. When he was working in Papua New Guinea in the 1980s intruders broke into his home and held a young woman guest, who was sleeping downstairs with the children, at knifepoint. They ransacked the house. “Had we kept a gun, like many expats, and fired it, she may well have got her throat cut. As it was, we lost our stuff but nobody was killed.”

In another incident, the 17-year-old daughter of an Australian history professor, a colleague of McIntosh’s, was abducted and gang-raped by 14 young men from a nearby squatter camp. Normally the police would have trashed the camp and beaten people up at random. But the daughter asked her father to find a way that would “touch their hearts”.

Her family, fellow Quakers, asked the police not to retaliate. “Her father and I went into the settlement and asked to meet with the leaders. They said they were very sorry about what had happened and very grateful we had asked the police not to cause any violence against them. We said, ‘We want you to do whatever would be an appropriate traditional ceremony of confession and reconciliation.’ On the appointed day the entire squatter community came out and with much beating of drums and bearing of token gifts, apologised, headed by the 14 men. Many had tears in their eyes.”

While McIntosh admits the reoffending rate might not have been zero, he believes it would be much lower than if they had been treated in kind. The case also shows an important contrast between violence and non-violence. “They operate on different timescales. The logic of violence only makes any sense in the short run. Non-violence, however, is a long-term and big-picture approach.” Sometimes officers come up to him after a talk, wondering whether they ought to stay in the military. He replies with what George Fox, the founder of the Quakers, told William Penn in the 17th century when Penn was vexed about wearing a sword: “Wear it as long as thou canst.”

He points to Mahatma Gandhi’s India, the relatively peaceful ousting of regimes in the Philippines and eastern Europe, South Africa’s Truth and Reconciliation Committee, even to some extent Northern Ireland, as vindications of the rationale of non- violence in recent times.

But pacifism is only one thread of McIntosh’s beliefs and outlook. Earlier this year he was invited to be a contestant on the TV game show Without Prejudice. Recruited by a TV researcher who had seen his website http://www.alastairmcintosh.com,/ he was told that Channel Four were looking for “strongly opinionated people” to debate topical social issues such as Iraq, gay adoption, fox-hunting, and capital punishment.

Despite not owning a television, McIntosh not only made it through the auditions to the programme itself, he scooped the £50,000 prize. The cheque was equivalent to 10 years’ pay for McIntosh, but he has mixed feelings about competing on the show. Not only were the views he expressed during filming heavily edited, he now believes the objective of the show was to allow the panellists to express their opinions rather than the contestants. Moreover, he was criticised afterwards for being “hypocritical” and “narcissistic”. On balance, he says, it was a worthwhile experience. “I’ve had loads of people come up to me in the street and say it really made them think about the spirtual underpinning of things, and it’s not the sort of thing they expect in prime-time TV. I do have feelings of ambiguity. If I had known at the outset what type of programme it was going to be I wouldn’t have gone on, but given the way it worked out, I am glad I did.”

He’s also something of an eco-warrior. In Soil And Soul, his fascinating and highly acclaimed book, published two years ago, he starts with his own Hebridean background, before delving into the full complexity of Scottish history, British empire, global economics, philosophy and poetry.

As well as recounting two major triumphs of the 1990s – he helped defeat plans to turn a majestic Hebridean mountain into a superquarry (after persuading a native American chief to testify at the government inquiry) and was a key figure behind the islanders’ buyout of Eigg – he explores notions of community and calls for nothing less than a “right relationship” with one another, with the earth’s resources and with spirituality.

He traces many of the world’s problems back to the 18th century Enlightenment, with its excess emphasis on rationality and material profit at the expense of humanity and co-operation. “The Enlightenment developed in response to the abuses of power in a society where power was mythologically validated – divine right and so on. Now the trouble is that movement has overshot; it has become stuck in its own head; it has cut off feeling, cut off value judgements.”

This has led, he says, to a heinous cornering of the earth’s resources – most damagingly oil and water – by huge multinational conglomerates. Incredulously, he holds up a Scottish Water bill for £769 charged to the GalGael Trust. He is treasurer of the voluntary organisation, which builds traditional boats with some of the most marginalised people in Glasgow’s deprived Govan area. It’s a one-person office: the sum is for one toilet and one sink for a year. “This is the kind of thing that makes me a campaigner,” he says.

So far, so liberal. Yet there is nothing woolly or ill-defined in McIntosh’s approach. “It’s about each of us taking responsibility for how f***ed up the world is, and I use that expression in its theological sense; Jeremiah 20 says words to that effect. We must recognise our complicity in it and confess that to ourselves. The problem now is we are in denial.”

Self-examination, an emphasis on personal integrity, is therefore a key tenet in McIntosh’s “spiritual activism”. “The management of natural resources is primarily a question about managing ourselves. We’ve got to ask: why are we so addicted to this oil economy? What have we done to let the multinational water corporations loose on the fundamental source of life? So it’s a question of looking at ourselves in a psychological and spiritual sense.”

On a personal level, for him this means he should eat less meat, for example. He considers himself “addicted” to meat, a state of affairs that is “dysfunctional” given the ecological impact and cost. But does he not risk getting stuck on an endless guilt trip?

“I’ve no problem with guilt. I think it’s there for a reason, to give us a nudge into looking at who we are and what we’re becoming.”