What is the strategy? According to the Greek etymology, the strategy means "to conduct the army", Plato adding at once that the war, thus the strategy, must be submitted to the policy, the military art to that of the government. Before the Greeks, Sun Tzu (the VI-th century before J.C.) is the first theorist recognized as such of the strategy, his Art of the war being still studied by all the strategists and strategies and saving the surprising actuality, namely in view of the importance accorded by the Chinese thinker to the psychological and not military means in the war, phenomenon which characterizes more than any other strategic modern era of the nuclear. It will be necessary nevertheless to wait 1794 that the word strategy appears for the first time in our language, under the pen of the Prussian general Frierdrich Wilheim Bulow.