It took only forty-three seconds, less than a minute, to cause the disappearance of a city, with its dwellers and centuries-old history. One hundred and fifty thousand people literally vanished. That immense devastation was caused by the two atomic bombs dropped on Hiroshima and Nagasaki on 6 and 9 August 1945. Even for peaceful purposes, nuclear energy remains the object of harsh debates, especially in Europe; twenty years after Chernobyl, many countries still pay the price of the reactor number 4 explosion. Yet, in 2004 about 440 nuclear power plants have supplied, in thirty countries, 16% of the world electric power requirement. Of these plants, 140 are located in the United States, 60 in France. By the end of 2004, 26 new nuclear power plants were under construction, 18 of which in Asia. Atomic energy, its influence on the force relationships among countries and the world outlook with the use of alternative energy sources.