Paolo Cotta-Ramusino

Paolo Cotta-Ramusino is Secretary-General, Pugwash Conferences on Science and World Affairs(www.pugwash.org).

It is almost 65 years since the development of the first nuclear bomb, and yet we have had only two cases of use of nuclear weapons in war, namely Hiroshima and Nagasaki. So we have been spared the horror of a large nuclear war during this period when more than 130,000 nuclear weapons were built. This is a very unusual event in the history of mankind: so many weapons built, never to be used. Why has this happened? First, the leadership of the two nuclear superpowers and of the smaller nuclear States behaved as rational decision makers, as far as the control of nuclear weapons and the decision not to initiate their use were concerned.