Afghanistan: An Endless War?

David Cameron’s visit to Afghanistan today marks his first engagement with one of the thorniest foreign issues facing him. But while the extra money he has pledged to help the Army tackle roadside bombs is certainly welcome, it will do nothing to address the fundamental strategic dilemmas of allied involvement in Afghanistan.

Britain has more than 10,000 troops there, the largest force after the US. We sent more troops to boost President Obama's surge last December. The idea was to put into practice a US military doctrine transformed since 'shock and awe': take the ground with heavy commitments - another 20,000 US troops - but then concentrate on making civil government deliver for Afghans.

Yet six months on, it is hard to point to any real progress in the new surge. Meanwhile criticism grows of British strategy between 2006 and 2009: too few troops, too little preparation. British and US soldiers fight valiantly; aid pours in. But the basic problems remain: this is an open-ended war fought out in inhospitable terrain, in one of the world's poorest and most chaotic countries, against highly motivated guerrillas with little to lose. It is expensive: this year the war will cost us around £2.5 billion. It is bloody, with 294 British deaths since 2001, now running at several per week, as well as more than 1,000 Americans and countless thousands of Afghans.

Sooner or later, Mr Cameron will have to do what Mr Brown never managed: set out clear, achievable goals for British involvement in Afghanistan - and then get out.