PERHAPS the biggest lesson from 9/11 is that violence doesn’t really achieve anything other than pain and suffering.

What has al Qaida achieved by flying two planes into the Twin Towers and killing 3,000 people?

It has lost its stronghold in Afghanistan and it has done more harm to the people it purports to represent than to anyone else. It incited the US’s bellicose response which killed tens of thousands in Afghanistan and Iraq, and its own bombs kill more Muslims than any other religion. Its truck bomb on Saturday killed two civilians, one of whom is reported to have been a threeyear- old girl.

Indeed, its campaign has made life more awkward for ordinary Muslims in Britain and the US.

According to Foreign Secretary William Hague yesterday, al Qaida is now at its weakest point and is becoming “increasingly irrelevant”. Al Qaida’s political agenda has not been advanced one jot by 9/11.

But the US and her allies – including Britain – have not prospered with their violent responses, however legitimate, understandable and even necessary those responses might have been.

The war in Afghanistan, and then in Iraq, has lessened the terrorist threat from al Qaida and from rogue states, but at what cost to civilians and our soldiers?

Through Guantanamo Bay and Abu Ghraib, the allies’ reputations have been tarnished, and their military action has yet to bring political stability to the Gulf. It may have increased social instability at home instead.

The huge cost of the war is one reason why the US has run out of money and is losing its superpower status to China.

This weekend, pro-war supporters have claimed that the downfall of Saddam Hussein has positively triggered the Arab Spring. This is an interesting theory – but an alternative theory suggests that the Arab Spring might have removed Saddam and so rendered the Iraq war unnecessary.

These theories – these successes and failures – make good debating material.

But it is unarguable that the violence has created enduring pain and suffering, which was shown in the emotion of the 9/11 victims’ families yesterday, which is still so raw and so strong ten years on.