International Order

The Greek world did produce one solution to the tension between freedom and order, that is between city-state and empire, when Philip of Macedon (d. 336 B.C.E.) and his son, Alexander the Great (d. 323 B.C.E.), created a great empire stretching from Greece to the Indus Valley. At the core of that empire were the Greek city-states that Philip had conquered and united. He saw himself as bringing the Greek world to the fullest stage of development, creating a unified world order under Greek leadership. According to his biographer Arrian (second century C.E.) writing several centuries later, Alexander aimed at creating an empire that brought peace to the regions he had conquered but that would be administered by the Greeks. The goal was to create a cosmos polis, a world community in which all the members shared the sense of unity and brotherhood that the members of a traditional city-state shared. If Alexander had lived, he might have created a vast peaceful and orderly world community under a single imperial ruler. His early death, however, destroyed any possibility that such a community would actually be created. In the years after Alexander the Great's death, one school of Greek philosophers, the Stoics, followers of Zeno of Citium (c. 335–c. 263 B.C.E.), did develop the concept of mankind as forming a single community. This concept flourished subsequently among the Romans and, apparently, even helped shape the Christian notion of mankind as ultimately forming a single community.

The most extensive example of a stable international order in the ancient Western world was the Roman Empire. In the course of its history, first as the Roman Republic expanding to bring all of Italy south of the Po River under a single government and then in a series of wars, first against the Carthaginians in the West and then against the Macedonians and Greeks in the East, the Romans brought the entire Mediterranean basin under their control. By the time of the first emperor, Augustus (r. 27 B.C.E.–14 C.E.), Roman jurisdiction ran from northern England to the Syrian Desert and from the Rhine River south to the Atlas Mountains and the Sahara. The network of roads that the Romans constructed enabled them to keep the peace within the empire by dispatching troops rapidly when rebellion arose among the conquered peoples.

The Roman imperial order, the Pax Romana, succeeded because it relied not simply on Roman troops but on the Roman ability to obtain the cooperation of the leaders of the societies that they conquered. The peace treaty signed at the end of a war with Rome often held out to the leading men among the conquered people the possibility of Roman citizenship, that is membership in the ruling elite of the Roman world, to those who accepted the new order. This practice gave many of the conquered peoples a vested interest in keeping the peace. At the same time, the Romans generally abstained from interfering in the internal affairs of the states that they conquered, thus reducing possible points of conflict.

The gradual decline of the Roman Empire in the West beginning in the fourth century meant the end of the Pax Romana. Any possibility of a stable international order was lost as the Roman government collapsed and new populations moved into the lands that the Romans once ruled. The Carolingian Empire of the eighth and ninth centuries was a failed attempt to restore the peaceful order of the ancient Roman imperial world on Christian principles. In reality, however, there was no longer any possibility of a single dominant power exercising jurisdiction over a large region.