Noble sentiments, but the question still arises: What can a country like Britain do to protect its citizens against such an atrocity? It's not as if the security services weren't aware of the threat. Just a year ago, the former head of London's metropolitan police, Sir John Stevens, said it was not a matter of "if" London would be attacked but "when."
How do you defend, though, against an enemy with no formalized command structure and so well blended into local communities as to be almost invisible?
Rob Watson is a specialist on security issues for the BBC's World Service. He says one of the biggest difficulties facing the police is that the threat often comes from people with no previous criminal record.
"People are just not on the radar," Watson told RFE/RL. "What I mean by that is people who haven't followed the traditional route as Islamic extremists. They haven't trained in Afghanistan; they don't necessarily worship at a radical mosque; they don't have any criminal record and have no association with known groups that are being monitored. That is every security service's nightmare. You're looking for an extremist needle in a very, very large haystack."
Sometimes the security services succeed. This was not the first planned attack in London. British intelligence is believed to have thwarted five major plots by Al-Qaeda and yet on this occasion, it had no prior warning, not even a hint of what was coming. Indeed, so confident were the security services that on the eve of the G-8 summit in Scotland, they advised the government's Joint Terrorist Analysis Center to drop the security level in London from "severe general" to "substantial."
For all the stoicism, attitudes among the public are confused. How should an open society fight back?
"I think the danger is people will lose their rights and that's the worst thing that can happen really," said passerby Paul Griffiths. "I think it will be a dangerous thing if they do clamp down and we start to live in a police state."
"You don't want to have a backlash against the Muslim community in Britain," added another man, Chris Burgess. "You want to tighten up security but you don't want to infringe on people's rights."
Others took a less tolerant view.
"I think we should tighten up on the immigration because as you know they don't know how many people are being allowed into the country and the Muslims are actually serious," David Kay said.
But there are no ready answers. Some have suggested accelerating the introduction of identity cards, an issue that is already a political hot potato in Britain. But identity cards did nothing to prevent the bombings in Madrid last year.
Others have pointed to Israel as one state that has coped more or less successfully with the problem of suicide bombers. But Israel is a militarized state that is building a 10-meter high wall around its Palestinian population to contain the danger. These are not options that could have any sense or application in Britain.
Rob Watson believes that the British and other Western governments are resigned to a long war of nerves.
"I think that, in a way, what the government has been saying to people in this country is: you know, you do just have to get on with your lives," Watson said. "The implication being that this is a bit like the days when the IRA [Irish Republican Army] was attacking us. You can't stay at home, you have to get on with your work, with your lives, but we, the government, we, the authorities, can't promise you that it will be entirely risk- free."
In the meantime, governments from Britain to the United States to Iraq face a critical problem: How do they overcome the alienation and the anger that breed the bombers in the first place?
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