OPINION: What the West got wrong after 9/11
We all remember where we were when the planes hit the World Trade Center - and then the Pentagon and a field in Pennsylvania - 15 years ago this Sunday.
I was barely 20 years old, offshore in the Bay of Biscay as a volunteer able-bodied crewmember on a square red sailing ship for disabled people. Immediately, one had the feeling that the destiny of millions of people - perhaps many I knew - had been immediately changed.
For the officials in authority, it was likely even more jarring. For them, it meant nothing less than changing the way the West approached the world.
"The kaleidoscope has been shaken," British Prime Minister Tony Blair told the Labour Party conference less than a month later in a speech that promised to "reorder the world".
We will never know, of course, what might have happened if the West had responded differently.
Over the years, though, as every anniversary has passed, I've been struck by an ever-growing nagging thought: Did the reflexive response - perhaps even overreaction - make matters worse?
That's not to minimise the human tragedy - or, perhaps as important, the psychological impact of the assault. Nor is it to say the West should have ignored the threat from Osama bin Laden, al-Qaeda and Islamist militancy in general.
But with the distance of time, there seems a rather jarring mismatch between what actually happened and how we responded.
I was as guilty of that as anyone else. It's not that most of us necessarily saw a dramatic increase in Western military involvement in the region - Iraq as well as Afghanistan - as being a necessary response to what had just happened. It's just that it felt inevitable.
For years, many had known that the risk of high-casualty attacks was growing. Islamist militants had struck the Twin Towers before, with a 1993 car bomb that killed six people and wounded more than 1,000. Later, the 1998 bombings of the US embassies in Kenya and Tanzania demonstrated the attackers' ever-growing reach. So did the attack on USS Cole in October 2000.
The technology used in these attacks was never particularly sophisticated - bombs crammed into trucks and boats. What al-Qaeda was getting ever better at, however, was identifying points of vulnerability and exploiting them to increasingly devastating effect.
The death of almost 3,000 people on 9/11, however, left US intelligence and military chiefs feeling blindsided. Having failed to prevent the attack - or even predict one of such scale - they abruptly revised many of their expectations. "9/11 was seen as something which might take place every week," one former senior security official told me a decade later.
When Blair, in particular, comes back to justifying and explaining the Iraq invasion, that's the core of his argument. Al-Qaeda killed 3,000 on 9/11, but if they had been able to kill 3 million, he said, they would have done so. The threat of Iraqi weapons of mass destruction, therefore, could not be allowed to continue.
With hindsight, this was nonsense. Leaving aside the desperately imperfect knowledge of what Iraq might or might not have had, it assumed the consequences of invasion were easy to predict.
Philosophically, there was a substantial gap between right-wing neoconservatives such as Vice President Dick Cheney and more neoliberal interventionists such as Blair. Yet they came to the same conclusion: A more assertive military approach was central to both protecting the West and pushing back militancy by improving conditions in the poorer and more volatile regions of the world.
That thinking continued past President George W Bush and Blair into the Barack Obama and David Cameron administrations. Both endorsed their own regime change operations in Libya after the Arab Spring. And both made the same discovery - intervening is complicated, and sending large numbers of Western troops on theoretically time-limited missions inevitably achieves less than the planners hoped.
Nor, crucially, has it done much to significantly reduce the threat of militant attacks. Though the West had, until the attacks of the last two years, largely escaped more than occasional - if bloody - bombings, thousands died as militant groups instead struck in states such as Pakistan, Nigeria and, of course, Iraq and Afghanistan.
What we've now seen is something of a sea change in Western thinking. The military interventions now underway - against Islamic State in Iraq, the air strikes in Somalia, the much smaller campaign in Afghanistan - have a different flavour. For better or worse, the driving force is usually the local government. When US and allied troops and officials join the effort, it is in a supportive role rather than with the ambition of temporarily dominating the country before withdrawing. That makes more sense - even if political and military leaders have little appetite for talking about previous failures and just why they changed their tactics.
Working through local forces and power structures was, ironically, at the heart of the initially impressively successful 2001 operation to topple the Afghan Taliban. Those lessons, though, were swiftly lost against the backdrop of more grandiose, militarily conventional ambitions in Iraq.
The one place this strategy does not work is Syria. There, the United States remains desperately conflicted about whether it still wishes to bring down the government. It also finds itself squaring off against other governments, including Iran, Russia and now Turkey, that have very different perspectives and opinions.
The irony is that while so much of the intellectual and financial energy has gone into the larger wars since 9/11, the West has actually had considerable success on the counterterrorism front. Al-Qaeda was gradually dismantled, Bin Laden eventually found and killed. Through surveillance, intelligence, Special Forces troops and drones, militant operations have been disrupted.
None of that prevented the rise of Islamic State, which is now finding new techniques to hurt the West, particularly by radicalising individuals or tiny groups who can conduct hard-to-stop low-tech mass casualty attacks. But that shouldn't be surprising. Like using antibiotics to treat an infection, there will always be virulent new strains requiring a different treatment.
It's easy to say that attacks - and attackers - should be found and neutralised long before they strike. But that's never going to be entirely possible. What's important is to keep an eye on the real dangers and the real tools to mitigate them: limiting availability of weapons, not alienating large segments of the population so that they report potentially radicalised individuals. We need to avoid an overreaction that ends up polarising society, deepening divisions and just making everything worse. In Europe, unfortunately, things seem to be going exactly the opposite way.
The ultimate strategic bungle that opened the door to the attacks on New York and Washington was alarmingly banal. It should never have been possible for passengers on aircraft to be carrying lethal edged weaponry like the box-cutters used to kill the pilots. Nor should the attackers have been able to get access to the cockpit.
Still, 15 years after that terrible day, I can't help but wonder if we might have achieved more by simply doing less.
Peter Apps is Reuters global affairs columnist, writing on international affairs, globalisation, conflict and other issues. He is founder and executive director of the Project for Study of the 21st Century (PS21), a non-national, non-partisan, non-ideological think tank in London, New York and Washington. Before that, he spent 12 years as a reporter for Reuters covering defence, political risk and emerging markets. Since 2016, he has been a member of the British Army Reserve and the UK Labour Party.