Last Night's TV: 9/11: the Day That Changed the World/ITV1<br />Elegance and Decadence &ndash; the Age of the Regency/BBC4

It isn't easy to say new things about 9/11. Short of having Dick Cheney pitch up on screen and say, "OK... I'm sick of lying... we planned the whole thing in advance", it's quite hard to think of something that would really shake our received understanding of the event. But anniversaries come round and commissioning editors are as helplessly instinctive in their presence as a dog in front of a lamppost. So inevitably we get more documentaries in which those who were there run through the memories again. Channel 4 started things off on Wednesday night, focusing on the firefighters' experience, and last night ITV got in on the commemorative act with 9/11: the Day That Changed the World. Both of them replayed the same familiar footage of plane strikes and tower collapse (still compelling after countless viewings). And both of them captured the chaos and grief of the day. But what individual merit now comes down to in these things is usually fresh personnel and filled-in detail.

In both respects, 9/11: the Day That Changed the World had something reasonably special to offer. In terms of contributors, they'd got some of the people closest to President Bush on that day, from the chief of staff who had to whisper in his ear that America was being attacked, to Laura Bush, who was in the White House that morning, surrounded by frantic Secret Service officers who thought they were next. Not all their contributors were unprecedented scoops: Donald Rumsfeld participated in 9/11: State of Emergency a year ago, which could also boast Condoleezza Rice's impressions of the day. But they'd got a lot of the West Wing insiders who could offer a moment-by-moment account of top-level confusion and they had Rudy Giuliani, recalling what was surely the worst day a New York mayor has ever experienced, or is ever likely to. And again and again, it was the added nuances that stuck in the mind.

Bush's chief of staff, for instance, remembered stepping sharply away from the President as soon as he'd delivered his whispered briefing "so that he couldn't ask me a question". No wonder W looked a little lost, fed a line straight out of a Hollywood science-fiction movie, than left to dangle in front of a class of schoolchildren. Routine ran on for a few seconds, like Wile E Coyote over the abyss, before gravity reasserted itself. So steep was Air Force One's emergency take-off a little later that the President had to put out an arm to keep his Situation Room organiser in her seat. In Washington, Mrs Cheney had been rushed to join her husband in the presidential bunker and noted the surreal touch that fresh biscuits had been laid out on doilies.

Rudy Giuliani remembered a table-top detail too – his first intimation that the South Tower had collapsed reaching him by means of a classic Spielberg close-up, as the pens on his desk began to vibrate inexplicably. As he and his team tried to find a way out of the building they were in, one of his deputy mayors started to mutter the act of contrition to himself, convinced that they were about to die too. And their fear and confusion was matched on Air Force One where the President's security team were trying to second-guess where the next attack would come from. They went first to Barksdale Airforce Base in Louisiana, announcing their arrival only at the very last minute, and accompanying it with a shopping list that began with jet fuel and M-16 rifles and finished with 25lbs of bananas and 100 muffins. "Curt... we are living in a Tom Clancy novel," one of the commander's colleagues said to him as the plane lifted off again for Nebraska. There didn't appear to be cookies on the table when the President held a video-conference with Cheney and Rumsfeld in Washington, but by the time the neo-cons started work on the retaliation that night someone had laid out a full cookie assortment alongside bowls of M&Ms. In 20 years' time, we'll probably get that unsung hero's story too: "9/11: the Catering Corp Goes to War".

"I'm super-keen to channel a bit of butch Regency style," said Lucy Worsley in Elegance and Decadence – the Age of the Regency, her history of the Regency period. She's super-keen full stop, frankly, always happy to dive into the dressing-up box or do a bit of skippy pantomime across the screen. Only one thing stilled her relentless cheeriness, which was unwrapping battlefield souvenirs Byron had sent back to his publisher from Waterloo. Cockades and buttons and cannon shot, touched by the poet and, before him, by men at the heart of a historic moment. It's the details that do it.

t.sutcliffe@independent.co.uk