Duncan Sperry's debut novel is called Fault Line . The title refers to the physical cracks across the planet which often lead to political divisions.

Pakistan's border is an example which figures in his book. Tensions between Pakistan, India and China run high where steep mountains and deep valleys separate people.

Duncan is fascinated by how the geological fault lines which create beautiful scenery can also carve ugly differences. It has long been this way. But, he says, the risk of fault lines around the world fracturing is greater than ever.

"What's changed over the years is the ability of the little guy to use weapons and all types of means to put themselves in the same position as the big guys. Whether that's the Taliban, IS, various factions on the Indian sub-continent or individual terrorists, there is the ability to create chaos with very little resources.

"You go back to my childhood and you had east and west, the Cold War. That's all dissolved. 'Know thine enemy.' It's now 'Who is mine enemy?' The book tries to reflect that complete unknown of who we're dealing with. It causes geographical and political lines to blur. My interest is how the geo-political chaos plays out."

Such concerns have been sparked by Duncan's varied experiences. A youthful-looking 60, he spent seven years as an army captain and has travelled the world as a mountaineer and a businessman.

Sandhurst-trained, he has the quiet confidence you might expect of an officer. It's easy to imagine this relaxed demeanour serving him well during his work in more than 40 countries. Duncan has spent much time in the Middle East, South East Asia and the Indian subcontinent.

He worked for companies including banknote and passport maker De La Rue, and Verifone; the world's largest manufacturer of credit card payment terminals. This might not sound as exciting as the army or the mountains. But it had its moments.

"I was having adventures in business," is Duncan's description. "I was negotiating major contracts with De La Rue for passports and ID systems. I went into the Lebanon, to Beirut, to get the sign-off for the diplomatic passports, three weeks after Terry Waite was kidnapped there. A big black car picked me up from the airport. I didn't know which side they were on.

"I was at Kampala [in Uganda] in a period of civil strife. I went round a corner and this boy stuck a Kalashnikov in my belly. He looked like a 10- or 11-year-old. He was probably 15 or 16."

What happened? "I grinned, and he grinned. I gave him some sweets."

He smiles at the memory. But Duncan knows this was a minor victory in a bigger, bleaker picture. "The most awful thing is the brutalisation of children at a very young age. Childhoods are robbed. That causes a really big problem for the future. A generation of children in Syria know nothing different to bombing and living in a wasteland."

Home is the north Pennines beyond Brampton. Even such a remote location cannot guarantee protection from the wider world. In Fault Line , the repercussions of actions thousands of miles away follow main character Philip Dunstan to rural Wales, Oxfordshire and the Scottish Highlands.

Dunstan's internet payments business is under attack. His company is being used by a money-laundering operation, his right-hand man has been murdered and his executive assistant kidnapped.

The plot is played out across three continents. It's suspenseful with an authentic feel to the action and business scenes.

Philip Dunstan is a former soldier. Duncan is a payment security consultant. He insists the novel is not autobiographical, while acknowledging that it draws on his experiences.

"I'd been thinking about it for a long time. The challenge was that fact kept overtaking fiction. You write it and then it happens. Near the end of the book there's a concentration of events in a place in Pakistan called Abbottabad. I wrote about that one year before Osama bin Laden was taken out there. Sometimes you just can't make it up quick enough!

"That's part of the problem - things are fragmenting so quickly. A spark occurs and it accelerates so quickly into chaos. Pakistan. The schism between the various factions within Islam. That's yet to play out."

Fault lines... another of these runs within Duncan himself. Writing the novel was partly a way of working out who he really is.

"On one level I was trying to find out how my brain works," he says. "I was convinced that I was in the wrong mould for a lot of my life. My father was an aeronautical engineer. I was forced to do sciences and maths at A Level. I was always extremely uncomfortable with it.

"If your dad's an aeronautical engineer he just assumes you're going to be the same. Leaving school in the 1970s, it was just an expectation. I didn't kick back against it. Frankly, I wish I'd had the guts to push against it a long time ago. But it's never too late.

"I was trying to understand whether I had the creative aptitude to write a book. I now know I've got much more of a creative brain than a logical one. Once you start writing, the flow starts."

None of this means he regrets those years in the Royal Engineers, which included spells in Northern Ireland, the Middle East and the Gulf.

"The '80s were a much easier time than the 2000s, with Iraq and Afghanistan. The stresses we were under were much less in terms of combat. There were different tensions, especially in Northern Ireland. One had to gain a deeper understanding of the people and the environment, and to have a great deal of compassion and empathy. It wasn't 'That's the enemy, we shoot at them.' That taught one an awful lot about how it's not black and white.

"One of the bravest men I ever met was down on the border at County Fermanagh. He was a part-time RUC [Royal Ulster Constabulary] officer. He had three small children. He was a Catholic. [The RUC was predominantly Protestant and Catholic officers were frequently targeted]. I remember having tea in his sitting room. He's got these shotguns and other weapons in a cabinet. They'd tried to kill him four times. After I left Ireland he was killed... that's bravery."

What did Duncan take away from his time in the military? "The thing one should take away is a deeper understanding of humanity. What I took away comes through in the book. One man's terrorist is another man's freedom fighter, for example. I'm not excusing terrorism in any shape or form. There's gross acts of cowardice. But ideological causes are often based on extraordinary injustices, such as the partition between India and Pakistan.

"You have to fight injustice. But you can't fight ideology. Certainly not with arms. You have to do it through hearts and minds. We didn't do that in Iraq. We did it a bit more in Afghanistan."

His army years helped satisfy the urge for adventure which has always been there. Duncan remembers climbing over his grandparents' farm roof when he was four. At 14 he clambered 40ft up a bridge with no ropes.

The attraction of climbing sounds similar to the appeal of writing. It's "all to do with momentum and flow."

He's climbed in the Himalayas, the Alps and the Rockies. The toughest test was Mount McKinley in Alaska; North America's highest peak.

"We did a winter attempt in 1982. That was brutal. It was so cold. Everything was ceasing to function. We turned around about 1,000ft below the summit. We were getting frostbite as we were moving. With wind-chill the temperature was about minus 110."

Fault Line is dedicated to Sergeant John L Arthy; Duncan's former climbing partner. Sergeant Arthy died in a helicopter crash in the Falklands. Duncan quietly states that he has lost 25 friends in climbing accidents, crashes, explosions and shootings. Men who, like him, took their chances with a high-risk, high-reward existence.

Do these losses make him appreciate life more? "Oh yeah. It just makes you aware of the impermanence and fragility of life."

But his use of this knowledge has strained family life: Duncan is divorced with three grown-up children.

"It's caused me to do too much in the past, to try to achieve in too many areas. To try and pack too much in. Frankly that probably destroyed family life. You can't live several lives. You have to choose a life and live that. I'm much more relaxed than I used to be. I think the book's been pretty cathartic in that respect. It provides one with a focus. A furrow to plough."

Another furrow is his new business. Aurora Transact is an online platform which reduces the need for intermediaries such as banks and lawyers in business transactions.

"That's adventure," he says. "It's on the leading edge of technology. Life just continues to be an adventure. It might not be physical. It might be intellectual."