The anniversary of the September 11 attacks has spawned such a deluge of reminiscence and polemic that it is likely to overwhelm almost anyone. Instead of looking at the whole decade, it may be more useful to narrow the focus and concentrate on the experience of a single man.
That man is Abdul Hakim Belhaj, a former fighter in Afghanistan and victim of CIA rendition who is the hero of the liberation of Tripoli. His life story bears the scars of the mistakes of the post-September 11 decade, but also it might provide a hopeful sign for the future.
As commander of the Tripoli military council Mr Belhaj (he has not so far given himself any military rank) does not have time to dwell on the significance of anniversaries. His office is besieged by citizens who view him, in the absence of any meaningful government in Tripoli, as the man who can get things done.
Mr Belhaj's biography is extraordinary. He joined the US-backed rebellion against the Soviet-installed government in Afghanistan in 1988. He returned to Libya in 1994 where he joined the Libyan Islamic Fighting Group, an organisation dedicated to killing or overthrowing Col Muammar Qaddafi, and was later acclaimed as its emir.
This group was penetrated by Libyan authorities, forcing Mr Belhaj to flee. He made his way back to Afghanistan, and after the US bombed the Taliban government out of Kabul after the September 11 attacks, he wandered the world. In 2004 he was arrested by the CIA in Malaysia as a suspected Al Qaeda terrorist following a tip-off from British intelligence. He says he was tortured by the CIA for a few days and sent back to Libya, where he spent six years in solitary confinement.
While in jail he took part in a jihadist rehabilitation programme fronted by Col Qaddafi's son and putative heir, Saif Al Islam. The dialogue resulted in a document entitled "Corrective Studies on the Doctrine of Jihad" in which the detainees renounced the right to use violence against a government they felt was insufficiently Islamic. Mr Belhaj was released along with hundreds of other prisoners.
This was not a unique phenomenon. In Egypt in 1998, 2,000 members of Al Gamaa Al Islamiya were released from prison after the group renounced violence, although this led to a split with diehard factions.
With such a biography, it is hardly surprising that Mr Belhaj has set alarm bells ringing in the western countries backing the anti-Qaddafi uprising. There is a theory going around security-focused websites that the US is nurturing a new Osama bin Laden in Mr Belhaj. Just as US dollars funded the Afghan mujahideen who went on to harbour bin Laden, the argument goes, so western support for the Libyan rebels is going to turn that country into a jihadist-led state.
This is simplistic: the original sin of the US campaign to oust the Soviets from Afghanistan was letting Pakistan control the flow of money and arms. Pakistan insisted that it should be an exclusively Islamic jihad, and channelled the arms to the factions which best suited its interests. Nothing of the sort is happening in Libya. This was a spontaneous uprising, involving a broad section of the population in the east of the country.
Mr Belhaj captured the Qaddafi headquarters at Bab Al Aziziya for a simple reason: his Tripoli Brigade consisted of disciplined fighters with experience of war in Afghanistan, unlike the common run of Libyan revolutionaries, who brought only bravery and enthusiasm to the battle.
This is not to dismiss the very real tensions both inside the National Transitional Council, headed by exiles and former members of the Qaddafi regime, and between it and the fighters in Tripoli. Every day that the council delays establishing itself in Tripoli will tilt the balance of power further in favour of the men who captured the city.
Mr Belhaj's style is to speak slowly and deliberately and not to say very much. After four decades of empty rants from the deposed dictator, his tone and natural authority are a welcome change.
In speaking to the foreign media he says he is a democrat, and insists he never allied himself with Al Qaeda in Afghanistan, although he admits to fighting alongside its forces. His only interest, he says, is toppling the Libyan regime and setting up a constitutional government, not killing Jews and Christians as part of a bin Laden-style global jihad.
For years Mr Belhaj has been tagged with the "Al Qaeda affiliate" label, but that was a label that Qaddafi would often stick on his opponents as a way of gaining favour with the Americans.
The first lesson of September 11 is surely that President George W Bush's division of the world into those "with us" and those "against us" only served to create more enemies. It certainly turned Mr Belhaj, who at the time of his arrest was applying for asylum in Britain, into an enemy. He says that is all in the past, and now he is a grateful ally of the Americans.
The second lesson is that the Nato alliance cannot choose the next leader of Libya. Washington's record of picking leaders - Ahmad Chalabi in Iraq, Hamid Karzai in Afghanistan - is poor. As this choice is going to be watched closely throughout the whole Arab world it is more important than ever that the leadership emerges in a transparent way.
Finally, this weekend we should be studying not the post-September 11 wars but the Arab world's experience of social engagement with jihadists. This is not a panacea - it has not worked infallibly. But the history of the past two decades will show that the engaging with jihadists, and drawing out through dialogue the lessons of their failure, has had more positive effect than the $4 trillion (Dh14.7 trillion) spent on war.
If Mr Belhaj can prove a worthy addition to the Libyan leadership, it will show what a terrible mistake it was for the US and Britain to go around the world turning such people blindly into enemies. But we should be looking forward, not back.