Beaufort, By Ron Leshem, trans Evan Fallenberg

At the start of the invasion of Lebanon in 1982, the Israelis captured the Crusader castle of Beaufort. Ariel Sharon grabbed the chance to give a press conference in such a spectacular setting and announced a heroic achievement, accomplished without loss of Israeli life.

In the event, it turned out that six soldiers had been killed and that orders not to take the castle had either been misunderstood or ignored. But although the heroic narrative was tarnished, the Israelis were stuck with the castle, held until their retreat from Lebanon in 2000. Ron Leshem's powerful first novel tells the story of the last agonising months through the eyes of the final commando unit stationed there.

Beaufort, their gung-ho leader Erez tells us, "is living without a single second of privacy... With your eyes closed, and at any given moment, it's being able to name the guy who farted by smell alone". Leshem captures precisely what it is like for a group of young men to live in an intensely confined space, constantly on edge, surrounded by an unseen enemy who can launch a surprise attack at any time. Their interaction consists largely of macho putdowns and bragging about girls which cover up their grief for lost comrades and deep emotional interdependence. They also have to cope with the strange new tactics decided back at HQ, as when they are given a supply of mannequins to deceive the Lebanese about the number and positions of their troops.

It is bad enough to see your friends injured and killed, to have to collect up scattered body parts, when you feel you are acting in a good cause. But the action takes place at a time when Israeli public opinion and even the army are coming to see the occupation of Lebanon as pointless. Erez is haunted by the thoughts that all their hardships have been in vain and that some of his men "might possibly, in a crucial moment, fail to follow me in an attack".

Flamboyant yet gripping, the novel comes to a thrilling climax with the soldiers' perilous evacuation from Beaufort. Hezbollah is determined to inflict maximum damage as a propaganda coup, and Israeli plans to blow up the fortress, shelled almost daily for months, are almost scuppered by a Lebanese complaint to the UN about the destruction of a historic site!

Leshem brings us some sobering news, revealing how war is addictive as well as appalling, and how its terrible intensity can make ordinary life seem dull. As even crass Erez comes to realise, "I'm not really here to protect the northern residents of Israel but because I have this urge to kill."

Ron Leshem is speaking at Jewish Book Week on 2 March: www.jewishbookweek.com