The images are five years old, but already belong to a different era - flowers piled outside the US embassies round the world, Muslim women signing a petition of condolence in Jordan, candles and banners of sympathy held aloft in Bangladesh, and children standing for one minute's silence on the West Bank. So they go on, images of a world united briefly in sympathy for an America reeling and grieving from the attack on the Twin Towers and the deaths of almost 3,000 New Yorkers.
How moving but dated they seem today, when international Muslim public opinion (for this phenomenon does now exist) and the United States and its allies seem to stare at one another across an abyss of incomprehension and hostility.
But the cost of the struggle of the last five years against al-Qa'ida, which began after and as a result of those terrible events in New York, has been more than the profound alienation of the Muslim world. The West's claim to the moral high ground - the very image of democracy - has suffered an eclipse since Britain and other countries backed George Bush's misguided plan to "export democracy" to the Middle East and impose it there by force.
With the example of democracy Iraq-style haunting the Middle East for years to come - few will forget those images of monstrous abuse from Abu Ghraib - the concept has never posed less of a threat to the authoritarian rulers of states such as Egypt, Algeria, Saudi Arabia and Syria.
The arc of the stain created by that catastrophic venture - which the head of the Arab League, Amr Mussa, rightly warned would be like "opening the gates of hell" - has spread. Almost everything that has come into contact with it has suffered. Take the United Nations. Raised briefly after the collapse of the Soviet Union and the end of the Cold War, its image has suffered enormously from association with the Iraq war and the flagrant way the authority of the Security Council was borrowed as a fig-leaf for the US-led invasion. If the UN now shows regrettably few signs of being capable of tackling such crises as the genocide in Darfur, it is partly because of events linked to Iraq.
Then there is Afghanistan. Of all the strategic initiatives linked to the "war on terrorism", getting rid of the Taliban regime was the least controversial and most hopeful, not least because most Afghans clearly wanted this to happen. But the gains have been frittered away as troops and money have been diverted to Iraq, as this week's loss of life among British forces in Helmand province bears out.
While America and her allies expend money, prestige and soldiers' lives in an unwinnable struggle in Iraq, at home Americans have been persuaded by the alleged exigencies of the "war on terrorism" into conceding striking erosions of their own civil liberties, above all with the creation and continued existence of Guantanamo Bay. Five years on, it seems almost fantastic that more than 400 prisoners from the Afghan conflict still endure a bizarre existence in a legal limbo.
But here, too, we have felt the backwash of 11 September in myriad ways, not always immediately or obviously. An undoubted need to check the threat posed by home-grown sympathisers of al-Qa'ida has created an insidious momentum to chip away at civil liberties - a process to which our control-obsessed government has been instinctively predisposed. Critics of this creeping tendency have been routinely dismissed as dilettantes who don't understand the new, tough world order.
Many of these changes to the way we live are a more or less direct result of the way that America under Mr Bush, with help from Tony Blair, mishandled the challenge that al-Qa'ida threw down on 11 September 2001, dealing with the symptoms of terrorism when - as our own experience in Northern Ireland should have taught - it is the root causes of Muslim anger, especially in the Israel-Palestine conflict, that need to be addressed. Yet Messrs Bush and Blair have ignored that moral for the past five years, apparently persuaded that a show of military muscle was all that was needed. Somewhat forlornly, his power visibly ebbing away, Mr Blair was back in the Middle East this weekend, trying to kick-start a peace process that needed to be at the centre of everyone's calculations from the start.
So can we expect the response to 11 September, long since baptised as "the war on terrorism", to start moving in a more hopeful direction over the next five years? The runes do not look good. No US president looks likely to detach him or herself from Israel's armlock in the near future, and for that same reason the "Arab street" and the bigger "Muslim street", which includes about 2 million Muslims in Britain, are not going to be coaxed out of their growing, paranoid, distrust of America.
We can comfort ourselves with the handful of mini-triumphs since 2001. Iraq's long suffering Kurds have undergone a renaissance, while Libya under Muammar Gaddafi has been converted to good behaviour. Various planned terrorist atrocities have been foiled in Britain and elsewhere.
But it is not an impressive balance sheet weighed against the recent striking reverses in Afghanistan, the carnage in non-Kurdish Iraq, the dangerous rise of Iran to regional superpower status, Hizbollah's quantum leap forward in Lebanon and - for all roads lead back there - the Palestine-Israel conflict.
All the factors that have given rise to sporadic but very determined and bloodthirsty acts of terror, in Bali, Madrid and London, remain in place. Nothing has really moved on; opinions have merely hardened on both sides. Ever more invasive security measures may reduce the threat to what Norman Mailer has called a "tolerable level" of terrorism. In the current circumstances, after so many lost opportunities, we should not expect more.