'TERRORISM!' It was the first thought of many New Yorkers when the earth contorted in a quake that rocked the American north-east in the weeks before this 10th anniversary of the September 11 attacks.

It has been a tumultuous decade - for New York and Washington and for the world. Wandering the streets of lower Manhattan today kindles haunting memories for me - of tearful, stricken crowds running uptown as I legged it downtown; disbelief that the first of the twin towers had actually collapsed; sheer terror as the second tower began to pancake; me racing ahead of a grotesque, animal-like cloud of debris as I retreated uptown. Then the hand of a cleaner, who opened the side door of a bank building, yanking me to safety in the split-second before the streets around us were wrapped in dust, darkness and death.

Glogowski, an engineer, distraught but grateful for an inexplicable decision to switch from high heels to flats on leaving her Brooklyn home that morning, wandered away from the World Trade Centre towards home, convinced the world was ending.

After phoning in my reports for 11 editions of The Age and The Sydney Morning Herald, I volunteered at an emergency field hospital at the Chelsea Piers on the Hudson River.

As we donned gowns, a doctor explained the colour-coded tags we would find on the toes of the injured as they were brought in - black, red or yellow, depending on their chance of survival. ''If it looks like they're going to die, let them,'' he insisted. ''There will be a lot more coming in that you'll be able to save.'' But there were so few survivors, and not one was brought to the field hospital.

Ten years on, Glogowski seems cheerfully and gratefully Christian - ''I asked God to save me and that is why I'm standing before you today.''

Cleared of more than 100,000 truckloads of rubble, the 6.5-hectare site was idle for years. It was not until 2006 that governments, developers, insurers and victims' families could agree on how to redevelop the site as a commercial venture and memorial that today carries a price tag of $US11 billion ($A10.4 billion).

The term ''finished'' is loosely applied to an impressive memorial of hundreds of swamp white oaks and two huge water features that use the basement footprints of the twin towers. But guests at today's commemoration will find themselves amid the controlled chaos of a giant construction site and dwarfed by glass sheaths that are new towers, rising to heights of up to 541.3 metres. No cost has been spared on what, at $US700 million, is billed as the world's most expensive memorial.

Lower Manhattan is getting on with life, mayor Michael Bloomberg celebrating ''one of the greatest comebacks in American history''. He lists a near doubling of the population, 19 new hotels, eight new schools and a slew of expanded or new businesses.

Despite, or perhaps because of, the economic crisis, New York has returned to what Americans would describe as its ''hard-ass'' self. ''A lot of the compassion and connection between people that we saw in the months after 9/11 has eroded,'' David Friend, a Vanity Fair editor and author of a book on the imagery of the attacks, says. ''There's a buried shell-shock, a hidden sense of trauma - the first reaction to the August 23 was, 'Is this a terrorist attack?' ''

The language is moving on, too. The tallest of the new structures at Ground Zero was to be Freedom Tower. But, according to the New York Post, that caused many to cringe and it has become what real estate agents judge to be the more marketable 1 World Trade Centre. The term Ground Zero is also frowned on because it implied inaction. And Washington does not mention ''the war on terror''.

Friend, whose corporate employer, Conde Nast, has become one of the first to sign on for space in the new complex, does not see New Yorkers rushing to deep reflection about Osama bin Laden's motives. ''The reaction still is very much 'f--- al-Qaeda','' he says.

Here, however, pollsters do detect a shift. The Pew Charitable Trust found that 43 per cent of Americans today, compared with 33 per cent in September 2001, think US wrongdoing might have motivated the attacks. But this is a development that could be influenced by the lack of news coverage. The war in Afghanistan costs US taxpayers $US2 billion a week. But, according to the Nieman Watchdog, the nation's main TV newscasts devote an average of 21 seconds each bulletin to the conflict. Likewise, Afghanistan last year commanded just 4 per cent of newspaper news space - significantly more than Iraq at 1 per cent. Given the multi-trillion-dollar US security bill since September 11, there is a disconnect that is disturbing.

We will debate forever how much the world has changed in the past decade, but the answer might well be - not a lot.

Led by the US, Western forces proved able invaders, with the military campaigns to dislodge the Taliban in Afghanistan and Saddam Hussein in Iraq logistical marvels. But as occupiers and nation-builders, the performance has been dismal.

The American Interest magazine's Adam Garfinkle writes: ''And so in the 9/11 decade this is how we got a war against Iraq that destroyed the regional balance to Iranian hegemonism and did not even stop to ask about the broader implications of a Shiite government in Baghdad … So too did we turn what should have remained a punitive military operation in Afghanistan into, first, an occupation and, then, a quixotic, distracted, chronically underfunded, diffusely managed and thus hopeless nation.''

In focusing on the September 11 decade, we also should contrast it with the wider spans of history. And just as Barack Obama has held on to almost all Bush-Cheney policy and security architecture, the policy drivers are historically consistent, writes Melvyn Leffler in Foreign Affairs. The attacks ''did not transform the long-term trajectory of US grand strategy'', he says. ''The US's quest for primacy, its desire to lead the world, its preference for an open door and free markets, its concern with military supremacy, its readiness to act unilaterally when deemed necessary … all these remained, and remain unchanged.''

Terrorism specialist Peter Bergen says ''bin Ladenism'' would never enjoy the mass appeal of other destructive ideologies, such as communism, but does that mean that the West overreacted? The answer 10 years on would be ''no … and yes''.

No, in terms of assessing the threat from al-Qaeda, but yes in the botched handling of two wars that made the counterterrorism challenge so much more difficult and complex than it had to be.

Writing last week, the former US assistant secretary of defence Joseph Nye observes: ''A key lesson of 9/11 is that hard military power is essential in countering terrorism by the likes of bin Laden, but that the soft power of ideas and legitimacy is essential for winning the hearts and minds of the mainstream Muslim populations from whom al-Qaeda would like to recruit.''

The decade was almost too neatly bookended by the September 11 attacks and the killing by the US this May of bin Laden. The al-Qaeda leader died perhaps only half appreciating the error of his way. Just as the US believed it might counter al-Qaeda's ideas with brute force, bin Laden believed he could impose them with the suicide bomb and mass murder.

But this year there has been less al-Qaeda violence than in any since 2001 and The Guardian quotes a British security source: ''Al-Qaeda has been hollowed out - of the top 10 people we were interested in a few years ago, only one is still alive.'' Al-Qaeda inflicted what terrorism expert Michael Scheuer describes as a near-mortal self-inflicted wound in its brutal slaughter of thousands of Muslims in Iraq.

Bin Laden made an even greater error in reckoning on the support of Muslim youth. He had called for a multi-generational jihad and predicted that his death would act as ''a beacon that arouses the zeal and determination of my followers''.

It didn't happen. Instead, the world has been transfixed for the past nine months by what is called the Arab Spring or awakening and Nigel Inkster, a former deputy director of Britain's MI6, declares that ''bin Laden's ideas … of sparking a global insurgency have been and gone''.

Here there's an important caveat - and this is where the global response to the Arab awakening might be a better measure of the extent to which we have changed.

Right now, Washington and other Western capitals are doing what they have always done - picking winners and losers in the Arab revolts according to their own vested interests. Libya, Egypt and Tunisia - good; Syria, Bahrain and Yemen - bad.

But if the people of these ''bad'' countries are left to their fate, under the heel of the likes of Syria's Bashar al-Assad, it would be hard to blame them if they were to turn to the remnants of al-Qaeda, a movement that wants rid of the Arab autocrats as badly as the West does.