Gwynne Dyer is a Canadian-born independent journalist whose column is published in more than 175 papers in 45 countries.

‘Changed the world forever’ is the most hackneyed phrase in journalism, and if you can get through this week (the 20th anniversary of the 9/11 attacks) without hearing it half a dozen times you’ll be very lucky.

With the benefit of hindsight, how much has the world changed as a result of 9/11? There was virtually no lasting impact on Latin America, sub-Saharan Africa, or East and South Asia, where even the phrase ‘9/11’ is meaningless to most people.

In Europe, no year had gone by since the 1970s without terror attacks by extreme left-wing groups like the Red Brigades and the Baader-Meinhof Gang or Palestinian operations like the Munich Olympics massacre, although Islamist activity pre-2001 was restricted to a few overflows from the Algerian civil war. No panic there.

Which leaves the ‘Greater Middle East’ (from the Arab world to Pakistan) and the United States itself.

Most Arab regimes were (and still are) absolute monarchies or military dictatorships, and although they doubtless felt a little frisson of delight at seeing Americans on the receiving end for a change, their main concern was for themselves.

Would this threaten their own survival?

The main domestic opposition in all of them was (mostly illegal) Islamic parties. Would Osama bin Laden’s spectacular attack radicalise those groups into full-blown Islamists with enough popular support to drive the existing regimes from power? That’s what bin Laden was hoping for, but it turned out that the support for Islamism was still too thin.

The only Arab leader to fall because of 9/11 was the unfortunate Saddam Hussein of Iraq, who got invaded and killed by the Bush administration essentially because the invasion of Afghanistan had not slaked the American public’s thirst for revenge on somebody or other.

Saddam had nothing to do with the terrorists (and he didn’t have any weapons of mass destruction either), but he was a murderous dictator and Iraq paid the price. Pity about all the dead Iraqis and their wrecked country, but they were just in the wrong place at the wrong time.

So there were really no big changes in the Arab world as a result of 9/11, and that goes for the rest of the Middle East too. Ayatollah Ali Khamenei is still the Supreme Leader of Iran, the army still really runs Pakistan (behind a civilian facade), and as of last month the Taliban are running Afghanistan again.

Even in the United States itself, the damage was relatively modest: almost 3,000 civilian dead on the day, and another 6,800 military deaths in subsequent twenty years while a generation of American soldiers hunted down Iraqis and Afghans the vast majority of whom never posed any threat to the American homeland. They just didn’t like being invaded.

Any other costs? Well, around 900,000 people killed and eight trillion dollars wasted, according to a new report from the ‘Costs of War’ project at Brown University. But most of those deaths were just ‘collateral damage’, and the US military-industrial-academic complex would almost certainly have found other excuses for that scale of spending if 9/11 hadn’t happened.

Did the world change forever? No, it barely budged. 9/11 was a deliberate provocation and the United States fell for it hook, line and sinker, but it still didn’t produce any of the changes the perpetrators wanted – or any other big changes either.

The only lesson we can learn from it is that spectacular, terrible events are not necessarily the same as real changes. Indeed, they usually aren’t.

Gwynne Dyer’s new book is ‘The Shortest History of War’.