On 23 October 1983 a suicide attack on US marines killed 241 Americans. But President Ronald Reagan never hit back at the Iranian and Syrian conspirators. Now we know the reason why.

The Knife Edge tells for the first time why the West walked away from Lebanon and opened the way to decades of chaos. It shows that in a bleak bargain with history the Americans had stepped back from the risk of a devastating global conflagration. Full of intrigue, espionage and revelation, it is a true story that will chill anyone who recognizes many of the same dangers today.