Writer, conservationist and adventurer Rory Stewart has walked 6,000 miles across Asia and speaks Urdu, Farsi, Dari and Nepali. A former soldier, diplomat and Harvard Fellow, he was coalition deputy governor of two southern Iraq provinces, and now runs a regeneration project and centre for traditional craftsmanship in Kabul. Unrivalled for his grass-roots knowledge of the region, his opinions are sought by presidents and princes, politicians and the press. He is 35.

Like many Scots who made their name abroad, Rory maintains a deep attachment to his homeland, and returns regularly to his Perthshire estate. I found him recently engrossed in plans for relandscaping the park, mulling over Repton’s theories of the Picturesque. Swinging through the mud in full High-land garb, he showed me a water meadow dug by Napoleonic prisoners, ancient woodlands and a Neolithic site, recounting their history with pride. In many ways, he resembles a hero from a former age, with his curiosity for learning and physical stamina, his distinctive sartorial style and staunch principles of self-discipline and service to his country. Yet he is far from old-fashioned: few Westerners involved in Afghanistan and Iraq today have a better understanding of the people and their political complexities.

The background to this astonishing career was a childhood spent in the Far East, during which he experienced such extremes of adventure and conformity as only a diplomatic childhood can bring: unbridled freedom in the Borneo jungle; prep school in Oxfordshire. Then Eton and a summer tutoring Princes William and Harry, followed by a short commission in the Black Watch. After Oxford, Rory joined the Foreign Office and was sent to Indonesia, where he found the country in the grip of an economic crisis precipitated by the toppling of President Suharto. There, and in Montenegro in the wake of the Kosovo invasion, he gained direct experience of post-conflict foreign intervention and found the effects to be generally positive. Later, he was to form a rather different opinion.

First, however, he took two years off to walk from the Turkish border to eastern Nepal, crossing Iran, Pakistan, India and Nepal in 16 months. Visa problems demanded that he do Afghanistan later. ‘It’s mid-winter,’ a security service official warned. ‘There’s 10ft of snow on the high passes, there are wolves and this is a war. You will die, I can guarantee.’ That epic journey, tracing the footsteps of the first Mughal emperor Babur from Herat to Kabul, is detailed in his award-winning book The Places In Between. ‘I’m convinced that walking is the way to experience a country the accidental nature of where you stop; the slow approach to landscapes,’ he says. Rory arrived in Iraq supporting the war, but realises now that ‘we achieved very little’, and that the invasion was ‘a mistake and a failure’. His book Occupational Hazards records his experiences, including a three-day siege and mortar attack at the compound in Nasiriyah.

Disillusioned with the naïve intentions of foreign officials and development agencies, he has demonstrated at the Turquoise Mountain Foundation, which he set up in 2006, how ‘confidence and taking risks’ can be more productive than endless ‘needs assessments’ and ‘gender and civil society workshops’. His work in the medieval heart of Kabul, restoring buildings, reviving traditional skills and creating jobs, has helped rekindle a sense of national pride and identity.

He is upbeat about Afghanistan’s future: ‘Afghans are incredily resilient. No, I’m much more worried about Scotland; we don’t know what sort of country we are any more. We’ve lost our values and identity; people seem so apolitical.’ He talks of returning home soon to spend time in Britain, ‘finding out where we’re getting to’, and possibly of going into politics. One thing seems clear: wherever he goes next, Rory Stewart is likely to achieve something remarkable.