"The pace of change and the growing lethality of weapons have gone on accelerating ever since. Think of the flimsy, single-engined, unarmed planes which took to the skies in 1914 at the start of the First World War and compare them to the faster and more powerful ones that had emerged by 1918, capable of firing machine guns and dropping heavy bombs on the enemy. By the end of the Second World War aircraft were flying higher, faster, further and carrying much greater loads, and the jet engine was starting to replace propellers. When the American bombs fell on Hiroshima and Nagasaki in August 1945, the new and terrifying nuclear age was inaugurated. Today new weapons, from fighter planes to aircraft carriers, are often obsolete by the time they are in service. The world’s arsenals are immense: it is estimated that there are over a billion small arms alone in the world and, at the other extreme, nuclear weapons capable of destroying humanity several times over. And serious disarmament measures remain more distant than ever. Yet so many of us, our leaders included, still talk of war as a reasonable and manageable tool."