On July 7, 2005, four suicide bombers killed 52 people in central London, and injured more than 770.
Almost eight years on, the capital is again reeling from a terror attack, after the gruesome killing of soldier Lee Rigby in broad daylight in Woolwich.
This raises the awkward question of whether Britain's community relations have managed to improve in the past eight years.
Where the BNP mopped up far-right sympathisers in 2005, today hooded members of the English Defence League march through Britain's towns and cities.
The EDL gather in south east London
The economy is in worse shape, which can fuel resentment, and immigration is top of the agenda thanks to the emergence of Ukip.
"The political climate is very much worse than 2005," former Home Secretary David Blunkett told The Guardian.
"We are living in a climate of very nasty and angry politics on issues like immigration and welfare at the moment, and it is building.
"We have to be very careful to make sure this does not tip over into something much more dangerous."
A Shadow Cabinet source told the same paper: "Fewer people were killed than at the London bombings, but the political context in which it has happened is worse than a decade ago.
"We tend to comfort ourself that the rise of Ukip has led to the decline of BNP. But the attitude to immigration and welfare has hardened from a decade ago."
But another former Home Secretary, Blackburn MP Jack Straw, did not agree. People were "genuinely fearful" after July 7, he told The Huffington Post UK. "Sikhs and Hindus were going on the tube and people were staring at them."
Straw pointed out that the BNP were "alive and kicking" in 2005 - they are seen as a fading force now, and are down to just two councillors.
The BNP has lost most of its seats
Straw also pointed to the reaction from the Muslim community. "There used to be a level of hesitation, sometimes equivocation, by mainstream Muslim organisations when this sort of thing happens. That's not the case now."
Throw in the departure from Iraq, and imminent exit from Afghanistan, and he believes society has moved on in the past eight years.
Sunder Katwala, the director of integration think-tank British Future, also pointed to the decline of the BNP - but warned that the EDL would be hoping the attack could provide a "lifeline" for them.
Katwala played down the influence of the economic slump, saying community relations were "more cultural than economic", and pointed out London was more resilient than anywhere in Britain, and possibly the world, when such incidents threaten cohesion.
"It seems to me to be fairly similar," he said. "The danger is of violence in the steret by a small nunber of people who want to do dangerous things."
There has been a spike in anti-Muslim incidents
Professor Matthew Goodwin, of Nottingham University, said confronting the far-right could be "more challenging" in 2013 than 2005. He said: "The BNP were focused on contesting elections.
"Now [the far-right] is more fragmented, more chaotic, less predictable, more preoccupied with confrontational demonstrations."
Despite it dominating the headlines, polls show that immigration is slightly less of a concern to people now than it was in 2005, Goodwin said.
The way religious extremists try to strike has also changed, he said, with less connection to organised networks.
"Everything's become less predictable," he added.
Farooq Murad, of the Muslim Council of Britain, had hoped the Olympics taking place in East London would allow community relations to "turn a page".
But overall he was optimistic, again pointing to the decline of the BNP. He said: "It seems that now, there is greater ability to handle, and put these attacks in perspective.
"I feel that the narrative is better and stronger and shows that progress has been made.
"If we all stand together, we will make another leap of progress."