The Weekend's TV: Mark Knopfler: a Life in Songs, Fri, BBC4<br/>The Paedophile Hunters: This World, Sun, BBC2

Mark Knopfler. Remember him? The nice guy from Tyneside who fronted the band that never earned the same sex appeal of its eye-liner wearing, new romantic counterparts, but still managed to become one of the biggest stadium-fillers of the 1980s?

Dire Straits sold more than 120 million albums, yet few of us admitted to owning one even back then, and no one since has stopped to ask what came of its four band members. Did they burn out, fade out, die out?

This, the latest show in the Legends series, asked that question and we discovered that Knopfler broke up the band not because of their waning popularity, but the opposite. They got bigger and bigger, said Knopfler, until he just didn't want to play any more. What he loved was the "circus" camaraderie of the tours, which could not be sustained by the "big events" they became.

Knopfler appears now, at 61, an unchanged man, musically speaking, still obsessed with his Fender Stratocaster and still going strong as a solo artist, but he is so physically transformed that he can walk the streets without being recognised. The Bjorn Borg headband and sleeveless T-shirts have long gone and his scraggy shoulder-length hair is reduced to white head-stubble. We saw him lost in the crowds of a Lisbon café, where he sits unnoticed, opposite the stadium at which he is playing to a sell-out audience.

The documentary, which traced Knopfler's early life in Glasgow and the North-east and musical influences (boogie-woogie, The Everly Brothers, Bob Dylan), did not penetrate the depths of Knopfler's character so much as confirmed what we already suspected. Knopfler was and is earnest and well-adjusted, and that is perhaps why he never acquired that sixth-form fan worship or the Keith Richards brand of rock'n'roll cool.

The nicest surprises came not in going over Dire Straits's rise to fame, but in Knopfler's recollection of the inspiration for some of his best-known ballads, which encapsulate great story-like narratives. "Brothers in Arms" was partly born out of a conversation with his father during the Falklands war: "My dad remarked how ironic it was that the Russians were brothers in arms with a fascist dictatorship." "Money for Nothing", a wry take on the MTV generation, was written, impromptu, when he overheard a "meat-head" sort of a salesman in an electrical shop, commenting on the MTV channel on the shop's TV monitors. "I asked for a pen and paper and just started writing. That guy essentially gave me a song." "This Is Goodbye", meanwhile, arose from an article written by Ian McEwan about the last phone calls made by the victims of the Twin Tower attacks.

It was a curiously ironic personal story. It has been a conscious endeavour for Knopfler to make himself smaller, after first dreaming of becoming big.

The Paedophile Hunters: This World set up a moral conundrum by relating the paedophile crimes in Cambodia – namely the pimping of underage girls to Western paedophiles – to a history of American oppression and the legacy of the Khmer Rouge.

The documentary started out as a straightforward story of an American interventionist initiative, which sends out "paedophile hunters" to track down American sex criminals in South-east Asia who target foreign children for grooming. The aim of Operation Twisted Traveller is to have them extradited to the US for a far more draconian sentence than the soft punishment they receive in Cambodian courtrooms.

It began with the arrest of an American citizen suspected of kidnapping and raping a 12-year-old local girl in Cambodia, the "new sex-tourism paradise". The film crew was granted extraordinary access to the suspect, Ronald Adams, who was shown being arrested, as the camera panned across his apartment, which contained child porn and a collection of dildos.

America's Immigration and Customs Enforcement (ICE) agents were shown gathering evidence, talking to witnesses and suspected victims and discussing the moral responsibility for these sex-tourism crimes. One, Chris Materelli, saw it as a clear-cut case: "If Americans are coming to do this against Cambodians, it's our job to help Cambodia clean it up and bring that citizen to justice."

The documentary hinted at the fact that the intervention of these agents might one day become problematic: an agent was shown taking away evidence that the local police had not seized, and one reflected on whether the ICE agent and local police might one day end up operating two parallel or even competing investigations.

The film-makers probed the "historical" causes of Western paedophilia in the East, to touch on murkier ground of the poverty-induced complicity of Cambodian parents or guardians who sell their children to brothels and Western predators for a pittance.

It was never explicitly discussed but the story becomes complicated by America's historical responsibility to Cambodia. The nation's poverty was tracked back to America's carpet bombing during the Vietnam war and, after that, the horrors of the Khmer Rouge, which left a million dead, a third of the population under the age of 14, and millions vulnerable to poverty and abuse. The question of how far back responsibility of this kind stretches was asked but never answered.

a.akbar@independent.co.uk