It isn’t entirely true to say that the US-led Western intervention in Afghanistan has been an unmitigated disaster. For example, around 80 per cent of the Afghan population have access to basic health care, up from 9 per cent under the Taliban regime; more than eight million children, a third of them girls, are in education, compared to one million in 2001. But it cannot be denied that these successes have come at a huge cost in terms of blood – mostly, but certainly not exclusively, Afghan – and treasure. The United States has spent rather more than a trillion dollars there since 2001 and while other participants did not match the magnitude of America’s financial involvement, significant sums were nonetheless expended.

Despite this, the continued security and stability of Afghanistan remain on a knife edge. Although al-Qaeda has been expelled from Afghanistan and much of its original leadership killed or captured, the Taliban who harboured them remain a significant threat, particularly in the Pashtun south and east of the country, but