Operation Snakebite: The Explosive True Story of an Afghan Desert Siege
By Stephen Grey
Viking £16.99, 368 pages
FT Bookshop price: £13.59

A week before the fall of Saigon in 1975, US army colonel Harry G Summers Jr told his Vietnamese counterpart: “You know, you never beat us on the battlefield.” Colonel Tu responded: “That may be so, but it is also irrelevant.”

Citing this exchange, Stephen Grey broaches the central theme of his book on the British-led Nato campaign in Helmand, southern Afghanistan, in 2007-2008. Grey tells how over and over the enemy is crushed by sheer weight of force – mainly from the air – yet within weeks resistance has sprung up again.

A brigadier describes operations as “mowing the lawn”. A general admits to “killing lots of farmers”. Nato is now about to double its troop numbers in Helmand; Grey, a seasoned investigative reporter, offers a snapshot of what awaits them.

Operation Snakebite describes the recapture of Musa Qala, northern Helmand, in December 2007. In 2006 British troops were besieged for months there, and effectively abandoned the town to the Taliban. One year on, a renewed assault was launched, code-named “Operation Snakebite”, intended partly as an example of how to win over a local population with minimal destruction. Grey was embedded with troops in Helmand and recounts the story from their perspective. Though the book lacks a broader context, it is a fascinating insight into the reality of the Afghan war.

An ongoing Nato objective is to strengthen the police and Afghan National Army ultimately to control the country themselves. The ANA, then, was supposed to do the “heavy lifting” in this campaign. This was “all poppycock”, Grey insists: a 2,000lb bomb dropped by an F16 aircraft on a Taliban HQ was the turning point in the battle, he says; a Spectre gunship mowed down the survivors. After the town fell to the British and Americans, they hid their armoured vehicles in the back streets – the ANA ran up an Afghan flag for the cameras.

In Musa Qala much was made of the defection of Taliban leader Mullah Salaam. The mullah arrived to govern the town after its capture – lured by gifts of weapons and $64,000 in cash. But within months, British intelligence was convinced he was “the wrong Mullah Salaam” – a minor tribal elder, not a resistance leader.

Grey also provides glimpses of covert manhunts – described by a US general as “tracking down and getting the bad guys” – a hidden side of the public campaign to “win hearts and minds”.

The final chapter asks whether Nato’s ends correspond to its means; soldiers lament the absence of experts to repair war damage and deliver aid. Grey concludes: “You did get the sense of people clutching at straws to justify a war that many in high command and across government would say in private is a ghastly mistake.”

This book is neither for or against war. It’s the voice of an army trying to make sense of its predicament in Afghanistan. The result is a catalogue of doubt, criticism and anger. Politicians and generals – take note.

David Crouch is the FT’s assistant UK news editor