"It was like he wanted to be famous or something, but in a stupid way."
So spoke Joe Tallant, a witness to the actions of the man who had apparently butchered an off-duty soldier on a busy London street in broad daylight. With bloodied hands and carrying a meat cleaver, he danced around the dead body appealing for people to take pictures of him. He and his accomplice, a shyer character, waited for 20 minutes chatting to women who dared approach them, until armed police arrived. They made no attempt to escape.
In London on Wednesday afternoon there was a sense of shock and outrage at the hideous killing, but also puzzlement. How could this bizarre crime be labelled a terrorist incident? Terrorism, for Londoners, means a planned attack such as the four coordinated explosions on the Underground and bus network in 2005, which killed 52 people.
There was no doubt about the supposed political goal of the killing. As the more vocal of the killers wished shocked bystanders "Allah's peace and blessings", he said - in a London accent - "you people will never be safe" until British soldiers withdrew from Muslim lands. The aim of the operation, apparently, was to "start a war in London tonight".
But for the repulsive nature of the crime and the potential effect it will have on community relations in Britain, it is tempting to dismiss it as the action of a couple of violent and deranged inadequates.
Coming five weeks after the Boston Marathon bombing, it looks like a copycat operation. The two Boston terrorists failed to leave the scene on time, and were caught on surveillance cameras and chance mobile phone shots. Perhaps their insouciance made them bigger heroes in jihadist eyes. The London killers went one step further, offering themselves up for interview by smartphone while waiting for the police. Truly this was jihad for the YouTube generation.
While the investigation into the crime has barely begun, some light can be shed on this new type of terrorist by examining the case of Mohammed Merah, the petty criminal who last year went on a killing spree in southern France, killing three soldiers and then a rabbi and three children at a Jewish school. Merah had tried to commit suicide in prison and may have suffered from mental illness. After release, he travelled to Pakistan where he received weapons training.
There are two common themes here: attacks on the army and a "lone wolf" approach that lowers the chances of discovery by the ever more technically advanced and intrusive security services. As Jonathan Evans, then director general of MI5, the British security service, said last year, "lone actors attracted to extremism and violence" are a significant security threat, and one that is hard to detect.
The difficulties of keeping a serious jihadist network secret are well understood by the Al Qaeda affiliates in Pakistan and Yemen. That is why their internet propaganda encourages followers to act alone and use the weapons they have at hand: run over their victims by car and use knives or cook up bombs "in mom's kitchen".
These attacks may be crude and the perpetrators far from terrorist masterminds. But the fact remains that the scattered Al Qaeda affiliates are still exploiting the impressionable or those with a genuine grievance against the countries they live in. A policy response is required, and we can already see what it is going to be.
In Washington, the Boston bombing and the assault of the US consulate in Benghazi, Libya, have changed the atmosphere. Last year officials were close to declaring victory over Al Qaeda but now the "war on terror" is back on the agenda.
Michael Sheehan, a senior Pentagon official, was asked at a Senate hearing on May 16 how long he thought the "war against radical Islam, or terror" would last. "At least 10 to 20 years," he replied. Perhaps this is no surprise in a country where the wounds of September 11 are not healed but rather are kept raw by Washington's endless partisan sniping.
In Britain, the government was in the process of reducing some of the powers it has, or was planning to acquire, under antiterror legislation. Last month it dropped a planned law that would have allowed unparalleled interception of data about British citizens' online communications and voice calls. In 2011 Britain legislated for a slight relaxation in the curfew regimes of terror suspects who cannot be prosecuted, allowing them more freedom outside their homes.
Pressure is now growing for a review. Even before the forensic teams had left the crime scene, arguments were being made for enhanced data surveillance to catch the "lone wolves" through their internet usage. At the same time Baroness Neville-Jones, a former security minister, said that "internet hate preaching" was a serious problem that should be addressed, though it is not clear how this can be done except through Chinese-style censorship.
We should not be surprised that the Boston marathon bombing inspired imitators. Two weeks after the devastating 2005 bombings in London, another group tried a repeat, but none of the bombs exploded. So Wednesday's butchery may not be the last of the copycats.
The biggest danger at the moment is overreaction. In 2001, that led the US and its allies into a short-sighted decision to remake Afghanistan and then to impose democracy on Iraq by force of arms. For Britain, that uncomfortable period will come to an end when its troops will withdraw from Afghanistan next year.
The key issue is that the jihadists do not achieve their goal of forcing Muslim communities into "internal emigration" - withdrawing from British society into their own ghettoes. Every bomb or knife attack, even the most clumsy and dim-witted, serves that goal, due to the reaction it provokes from elements of the host population. All sections of society - Muslims, Christians and those of no faith - need to work together to isolate the extremists and prevent that happening.
On Twitter: @aphilps