Britain has long been one of the US’s staunchest allies in the Afghan war, one of a handful of Nato states taking on the heavy fighting against the Taliban in the south of the country. But the death of 15 British soldiers in Helmand province over the last two weeks – most of them killed in roadside bomb attacks – has triggered renewed debate over why the UK is in this war.

In part, the debate – as in many Nato member states – is over whether the international mission to defeat the Taliban can ever succeed. On this point, there is still more public support for the mission in Britain than in most European countries. The Guardian, the UK newspaper, on Monday published a poll showing that 46 per cent of people back Britain’s role in the conflict – a figure that has risen 15 points since the UK first went into Helmand in 2006.