After the first attempt had failed Xerxes repeated it on the greatest scale. Against the Hellenic nation, whose alien character was everywhere a hindrance in its path, the Orient arose in the east and the west for a decisive struggle; the Phœnician city of Carthage, the great sea power of the west, was in alliance with the Persian kingdom. Only the minority of the Hellenes joined in the defence; in the west the princes of Syracuse and Agrigentum, in the east Sparta and the Peloponnesian league, Athens, the cities of Eubœa and a few smaller powers. But in both fields of operation the Hellenes won a complete victory; the Carthaginians were defeated on the Himera, in the east Themistocles broke the base of the Persian position by destroying their sea power with the Athenian fleet that he had created, and on the battle-field of Platæa the Persian land forces were defeated by the superiority of the Greek armies of hoplites.
Thus the Hellenes had won the leading position in the world. For the moment there was no other power that could oppose them by land or sea; the Asiatic king never again ventured an attack on Greece. Her absolute military superiority was founded upon the national character, the energetic public spirit, the voluntary subordination to law and discipline and the capacity for conceiving and realising great political ideas. The Hellenes could gain and assert permanently the ascendency over the entire Mediterranean world, and impress upon it for all time the stamp of their nationality, provided only that they were united and saw the way to gather together all their resources into a single firmly knit great power.
But the Greeks were not able to meet this first and most urgent demand; though the days of particularism were irrevocably past, the idea which was so inseparably bound up with the very nature of Hellenism still exerted a powerful influence. As the individual communities were no longer able to maintain an independent existence, they gathered about the two powers that had gained the leadership, and each of which was striving for supremacy: the patriarchal military state of Sparta and the new progressive great power of Athens.
With the victory over the East it had been decided that the individuality of Hellenic culture, the intellectual liberty which gives free play to all vigorous powers in both material and intellectual life, had asserted itself; the future lay only along this way. Mighty was the advance that in all fields carried Greece along with gigantic strides; after only a few decades the time before the Persian wars seemed like a remote and long past antiquity.
But mighty as were the advancing strides of the nation in trade and industry, in wealth and all the luxury of civilisation, in art and science, all these attainments finally became factors of political disintegration. They furthered the unlimited development of individualism, which in custom and law and political life recognises no other rule than its own ego and its claims. The ideal world of the time of the sophists and the politics of an Alcibiades and a Lysander are the results of this development.
Athens perceived the political tasks that were set for the Hellenic people and ventured an attempt to perform them. They could be accomplished only by admitting the new ideas into the programme of democracy, by the foundation and extension of sea power, by an aggressive policy which aimed more and more at the subjection of the Greek world under the hegemony of one city. In consequence all opposing elements were forced under the banner of Sparta, which adopted the programme of conservatism and particularism, in order to strengthen its resistance, and restrict and, if possible, overcome its rival.
The conflict was inevitable, though both sides were reluctant to enter upon it; twenty years after the battle of Salamis it broke out. The fact that Athens was trying at the same time to continue the war against Persia and wrest Cyprus and Egypt from it gave her opponents the advantage; she had far overestimated her strength. After a struggle of eleven years (460-449 B.C.) Athens found herself compelled to make peace with Persia and free the Greek mainland, only retaining absolute control over the sea.
Under the rule of Pericles she consolidated her power, and the ideals that lived in her were embodied in splendid creations. She proved herself equal, in spite of all internal instability and crises, to a second attack of her Greek opponents (431-421 B.C.). But it again became evident that the radical democracy, which was now at the helm, had no grasp of the realities of the political situation; for the second time it stretched out its hand for the hegemony over all Hellas, in unnatural alliance with Alcibiades, the conscienceless, ambitious man who was aiming at the crown of Athens and Hellas.