Clare and I are sitting in the sunshine, drinking fennel tea. Nestled in her pashmina is Phoebe, an eight-week-old bull-terrier puppy who snores softly as we catch up on our human puppies. Francis is spending his gap year as a chalet boy in Verbier. Alexander is still at the prep school where our sons met. Georgia is at Oundle thank goodness, because Wyken is en route, so we meet before and after half-terms. Of all the mothers I got to know on the playing fields at Sam’s prep school, Clare is the one I’ve kept in closest touch with. She arrives like a Christmas cracker, full of surprises, gossip and tales of journeys with her husband, Edward, and children in her capacity as a travel writer for The Telegraph, hair-raising journeys that usually end up costing 10 times what they earn.

An hour with Clare raises my dopamine level for a week. But, for the past four years, there has always been a moment in our sessions when the conversation hits a sombre lull. It’s the moment when I ask her about Simon, her brother-in-law. Simon, son and grandson of captains of English cricket. Simon, Old Etonian, Sandhurst, Scots Guards, member of the SAS, and father, whose two eldest sons are officers in the British Army, serving in Iraq and Afghanistan. Simon, as in Simon Mann, who, since March 2004, has been a prisoner in Zimbabwe, where he and 69 others were arrested when their Boeing 727 was seized during a stop-off at Harare airport. His lawyer maintains that the plane was bound for the Republic of Congo to help secure diamond mines, but Simon is accused of leading an attempt to oust Equatorial Guinea’s President Teodoro Obiang Nguema Mbasogo.

Defending a soldier of fortune is not an easy job, but there’s a lot about Simon’s case that pushes me to do it. On purely legal grounds, he had served his four-year sentence (untried) in Zimbabwe and his lawyer believed that he might soon be released. As for the question of human rights, his vanished when a judge in the High Court in Harare ruled against Simon’s claim that it was unlawful to send him to Equatorial Guinea, a country where he would almost certainly be tortured and killed.

Two weeks later, he was ‘kidnapped’ in the dead of night, and flown out of the country. He’s now in a prison that Amnesty International describes as one of the worst in the world, kept in solitary confinement and permanently shackled hand and foot. Whatever the rights and wrongs of the former British commando, he’s paying the price for three pieces of modern history he couldn’t have foreseen. The first is that Robert Mugabe, having made his country destitute, would become a puppet of his oil-rich neighbouring dictator, delivering whatever Mr Mbasogo wants first on the list: ‘Mann for oil.’ Second, a British foreign policy that is interventionist when it suits, and hands-off when it comes to human rights.

But what may doom Simon Mann most will be words he has not heard. Guantanamo Bay. Abu Ghraib. Rendition. Waterboarding. When Western governments ignore international law and torture without constraint, they sign a blank cheque for unscrupulous governments. That he will survive, be freed and return to his wife and four young children including Arthur, the young son he has never seen is hope against hope.