The First World War has brought the emergence of Russia , British Empire , Italy , France , and United States . For the losers of the battle , it marked the disintegration of their empires , the demise of their economies and the disestablishment of their political systems . On the other hand , the Second World War was between Allied and Axis Powers . The most important outcome of this war is the emergence of the United States and the Soviet Union as the two most powerful nations...