THE UNIFORMS HAD been pressed, the boots polished and the soldiers drilled when President Hamid Karzai took his place on the podium to receive the salute from the Afghan honour guard.

Seven years after US-led forces ousted the Taleban, the independence day ceremony in Kabul this April should have been an occasion to celebrate the country's rebirth after decades of war and Taleban repression.

Instead militant gunmen had secretly positioned themselves in a nearby hotel with the intention of assassinating the Afghan leader, or at the very least ruin his party. Under a hail of bullets and to the deafening explosion of grenades, the honour guard took flight, foreign ambassadors and generals dived for cover and Karzai was ignominiously hurried away by his bodyguards. The assault, broadcast live on television, was a painful reminder of how unstable the country remains.

Sceptics predicted that Afghanistan's rehabilitation would be hard, but few imagined how little we would have to show for the billions of pounds invested and thousands of lives sacrificed trying to get the country back on its feet.

Afghanistan was meant to be the good war, in contrast to the invasion of Iraq. After an easy victory over the Taleban, America, with the full support of the international community, was supposed to transform the country into a democracy that would set the example for other Muslim states. After years as a pariah, Afghanistan should by now have been ready to take its place once more among the community of nations.

Ahmed Rashid's book is long, detailed and not for the faint-hearted. Here the foremost chronicler of modern Afghan and Pakistani history details how the Bush Administration, and the rest of the international community, failed utterly in one of the most important foreign policy challenges of our century.

Some of the setbacks, such as America's decision to launch the invasion of Iraq before it had finished the job in Afghanistan, have been well examined before. Here again Donald Rumsfeld is cast as the main villain, under whose direction the US continued to support warlords and failed to confront Pakistan for secretly supporting the Taleban and diverting resources away from Afghanistan. In one incredible decision taken in December 2005, the former Pentagon chief ordered 3,000 US troops to be withdrawn from southern Afghanistan just months before the resurgent Taleban launched its biggest offensive.

Rashid's most damning assessment is reserved for Pakistan, notably President Musharraf and his notorious military intelligence service, the ISI. The organisation helped to create the Taleban and even after 9/11 secretly continued to support the movement, helping it to rearm, retrain and give Taleban leaders safe haven in the Pakistani city of Quetta. America and Britain knew about this relationship, and even while their soldiers were being killed by the Taleban, they chose not to confront the Pakistanis. Cooperation with the ISI in combating al-Qaeda, whose leaders are based in Pakistan's tribal territories, was regarded as a priority. Nothing would be done to jeopardise that relationship.

The tactic has been a costly mistake. The resurgent Taleban has reasserted itself in Pakistan's tribal areas and southern Afghanistan. AlQaeda still operates under this umbrella. Roadside and suicide bombs, the two most devastating weapons used in Iraq, are now being employed with deadly effect.

Western forces were also in denial about Afghanistan's opium production, which today produces more heroin than the world can consume. Opium production is now Afghanistan's biggest industry, leading to massive Government corruption that has spread right to the President's closest advisors and even members of his family. Some of the profits are being diverted to fund Taleban military operations.

America, Britain and other Nato allies face their toughest challenge since the end of the Cold War. They are committing thousands more troops to Afghanistan in the knowledge that it will take decades to stabilise the country. Meanwhile casualty tolls are rising, public support for the war is dropping and locals are beginning to wonder if life might not be better under the Taleban. Defeat in this ugly contest would probably mean the end of Nato as a serious military alliance and the birth of a narco-terrorist state in Afghanistan.

It will not be of much comfort to read about the missed opportunities in Descent into Chaos, but perhaps those involved in the fight might avoid repeating the same mistakes.

Descent Into Chaos: How the war against Islamic extremism is being lost in Pakistan, Afghanistan and Central Asia by Ahmed Rashid

Allen Lane, £25; 484pp Buy the book here from Books First £22.50 including free delivery

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