The cost of this 20-year military and security engagement has been astronomically high – in lives, in livelihoods and in money. Over 2,300 US servicemen and women have been killed and more than 20,000 injured, along with more than 450 Britons and hundreds more from other nationalities. But it is the Afghans themselves who have borne the brunt of the casualties, with over 60,000 members of the security forces killed and nearly twice that many civilians. The estimated financial cost to the US taxpayer is close to a staggering US$1 trillion. So the awkward question that has to be asked is: was it all worth it?