Book excerpt: Not by strength but by guile. Only since the Falklands campaign have the initials SBS become known to the public. Yet this clandestine formation of Britain's armed forces has been in existence since the Second World War. Barrie Pitt, who himself served with the SBS, describes how the it came into being in 1941. How they fought with distinction in the Aegean, where one of their exploits inspired The Guns of Navarone. How they earned rapport in the Adriatic, in Greece and in Italy. How the SBS was reorganised in 1946 as part of the Royal Marines and has since played a role in Korea, Borneo and the Falklands. Equally interesting is the author's report of the training and specialized skills required by the boat units, and the essential tasks facing them -- infiltration from the sea, reconnaissance, sabotage, survival, resistance to interrogation, escape from captivity -- and the expertise and determination to complete them. As Barrie Pitt's superb account of the formative years of this elite force shows, these qualities have been present from the very beginning. Barrie Pitt (1918-2006) was well known as a military historian and editor of Purnell's History of the Second World War and History of the First World War. His publications include 'Coronel and Falkland', 'Churchill and the Generals' and 'The Crucible of War', a trilogy covering the North African campaign of the Second World War. He was born in Galway and later lived near Ilminster in Somerset.