9/11 remembered: The new age of uncertainty

The US and its allies have achieved some of their goals over the past decade: Osama bin Laden and Saddam Hussein are now dead, Iraq and Afghanistan have democracy of a sort, and the Taliban and al-Qaida’s core group are diminished forces.

But other deadly terror threats have developed in Yemen, North Africa and Somalia; Iran and North Korea are pursuing nuclear weapons programmes; and parts of the Middle East still teeter constantly on the brink of war.

The War on Terror – former US President George W Bush’s phrase was never adopted by the UK, although much of the thinking behind it was – has had a huge cost in both human and financial terms.

Thousands of Western forces, including more than 550 British troops, have been killed in the Iraq and Afghanistan campaigns, and the death toll for Iraqis and Afghans is far higher.

Economists have estimated that the Iraq war will end up costing the US three trillion dollars, while the UK has already spent well over £20bn on fighting, diplomacy and reconstruction in Afghanistan and Iraq.

However, there has not been another successful Islamist terrorist attack on American soil, and al- Qaida has not managed to ignite a global Muslim insurgency.

Backed by an outpouring of anger and patriotic fervour, Bush’s response to the meticulously planned terrorist outrage was to unleash America’s unrivalled military might.

Within a month, US and UK forces had launched attacks on al- Qaida and the Taliban in Afghanistan, and within two months the capital Kabul had fallen.

Bush added to Washington’s list of enemies with the January 2002 speech in which he described Iran, Iraq and North Korea as the “axis of evil”.

But the invasion of Iraq in March 2003 provoked a major backlash against America as the successful military operation to overthrow Saddam gave way to administrative chaos and a vicious insurgency that claimed many tens of thousands of lives.

It was not until 2007, when the US introduced its “surge” strategy of sending in large numbers of extra troops, that the situation began to stabilise.

Meanwhile, the threat from Islamist terrorism has mutated, with spin-off groups and small cells inspired by al-Qaida providing new challenges for the security services.

The terror group leader Osama bin Laden was killed by US Navy Seals in a daring raid in Pakistan in May, but the terror movement continues under the leadership of his former deputy, Ayman al-Zawahri.

Yemen has become a base for another offshoot, al-Qaida in the Arabian Peninsula, which has been blamed for the failed attack on a flight to Detroit on Christmas Day 2009 and the printer cartridge bombs discovered on cargo flights in the UK and Dubai in October 2010.