The atomic weapons dropped on Hiroshima and Nagasaki in August 1945 heralded the arrival of a completely new era in international relations in which the framework of political decision-making about issues of war and peace was to be radically different from any period which went before it. Many questions remained about the weapons which had helped to end the Second World War, not least of which was, would they be the cause of World War Three? They undoubtedly communicated a message, the significance of which would become of concern to all human beings. The inevitable proliferation of such destructive technology, especially following the Russian acquisition of the bomb in 1949, meant that in future, wars-at least those between nuclear states-were increasingly unlikely to yield ‘winners’ and ‘losers’ in the sense that victory or defeat had been traditionally understood. But out of this realisation there gradually emerged some hope that surely no side would initiate a nuclear strike if, in so doing, it invited its own destruction.