Inside Story - The future of British troops in Afghanistan

British troops have been in Afghanistan for almost a decade. Sir David Richards, the chief of general staff, says the mission in Afghanistan could last for us long as 30 to 40 years. Liam Fox, the British defence secretary, recently said that British troops will be among the last to leave the country. So just what is the cost of the UK's military presence in Afghanistan and for how much longer will the UK keep paying that price?