The fear of a nuclear war has been present during all the period of the cold war. It has contributed to ensure a long period of peace, due to the "Mutually Assured Destruction" (MAD) concept. Whereas the Hiroshima atomic bomb liberated an energy of 20 kt, measured in equivalent tons of TNT, thermonuclear bombs release an energy equivalent to around 10 Mt, i.e. 500 times the energy of the Hiroshima bomb. It seems difficult to imagine the impact of such a bomb dropped over a big city. At the end of the Cold war, this danger seemed to vanish, but , presently, the threats seem to be back. There are different potential risks. One of them is the possibility of divertion from nuclear waste of dangerous material such as plutonium, which can be used for making a fission atomic bomb, but the main threat arises probably from the potential use of so called "tactical" nuclear weapons.
These nuclear weapons can be miniaturized ("mini-nukes"), and easily handled by many different carriers (artillery, aircrafts, missiles). At the end of the Cold war, a great share of these weapons were destroyed, but due to renewed tensions, this trend seems presently to have stopped. Such weapons have a very strong penetration power,and they have been more specially designed for destroying underground facilities. Their use might be considered for a "first strike", meant to achieve rapidly a decisive advantage. The main risk would be to decide using them in what might be presented initially as a limited conflict. Following such an event, a rapid escalation might happen, resulting in the destruction of a large proportion of the world human population.
These nuclear weapons can be miniaturized ("mini-nukes"), and easily handled by many different carriers (artillery, aircrafts, missiles). At the end of the Cold war, a great share of these weapons were destroyed, but due to renewed tensions, this trend seems presently to have stopped. Such weapons have a very strong penetration power,and they have been more specially designed for destroying underground facilities. Their use might be considered for a "first strike", meant to achieve rapidly a decisive advantage. The main risk would be to decide using them in what might be presented initially as a limited conflict. Following such an event, a rapid escalation might happen, resulting in the destruction of a large proportion of the world human population.
La menace d’une guerre nucléaire a occupé les esprits pendant toute la durée de la guerre froide. Paradoxalement, elle a contribué à assurer une longue période de paix, en raison de « l’équilibre de la terreur » qui s’était établi. La puissance d’une bombe nucléaire est exprimée en kt d’équivalent TNT. Alors que la bombe atomique à fission d’Hiroshima représentait environ 20 kt, une bombe thermonucléaire à fusion équivaut à 10 000 kt, soit 500 bombes d’Hiroshima. La puissance de ces bombes est généralement exprimée en Mt et peut atteindre 50 Mt. L’explosion de telles bombes sur des centres habités aurait un effet véritablement apocalyptique et toute riposte déclencherait des destructions similaires du côté opposé. Depuis la chute de l’ex-URSS et la fin de la guerre froide qu’elle était censée apporter, cette menace avait semblé s’éloigner. Toutefois, aujourd’hui, des menaces importantes planent à nouveau.
