The Hungarian emigre Edward Teller spent the best part of the twentieth century at the forefront of shaping national and world defence strategies. Few have had such a profound influence on the shape of the post-war world. He was involved at every stage of the building of the atomic bomb. In the years following the Second World War he was dubbed 'the father of the H-bomb' and assailed as the mastermind of a ruinous arms race - the original Dr Strangelove, his effigy burned by students who branded him a war criminal. In the view of the Nobel laureate Eugene Wigner, he was a 'great man' of vast imagination and one of the 'most thoughtful statesmen of science'. In the view of another, Isadore Rabi, he has been 'a danger to all that's important' and 'it would have been a better world without Teller'. Throughout his life he was at the centre of controversy, pursuing causes that drew the whole world deeper into the Cold War. In the process he alienated many of his scientific colleagues while providing the intellectual lead for politicians, the military and Presidents as they shaped Western policy towards the Soviets. Yet Sakharov, the Russian dissident and father of the Soviet H-bomb, dec