War and Foreign Policy
in Republic Book IV

Jim Hamm (University of Minnesota)

This paper will address the “foreign policy” of Kallipolis in Plato’s Republic. Should expansion be deemed necessary by the city’s Guardian class, the means at their disposal would seem to include the tactic of instigating civil unrest in other cities through appeal to self-aggrandizement and self-interest, doctrines foreign to and outlawed from their own city. A dilemma thus arises: Why should and how can a state that is internally constituted to achieve a moral order act from purely self-interested and utilitarian motives in its international affairs? Does justice in fact stop at the gates of Kallipolis?

An important, if infrequently noted, passage in the Republic discusses the “rules of engagement” permitted to Kallipolis in the event of war. Following Socrates’ argument at the beginning of Book IV that wealth must be kept out of the hands of the Guardians, Adeimantus asks, How will our city be able to wage war when it is not in possession of money, especially when it is compelled to wage war (anagkasthēi polemein) against a large and wealthy city? (422a). Socrates replies that the Guardians, when acting as “competitors in war” (polemou athlētai), will ultimately prevail against the rich of opposing cities who, by nature of habits induced by wealth, will be less capable as soldiers (422c). Socrates further argues that since other cities are not be as unified as Kallipolis, the Guardians, who have no desire for wealth per se, will be able to exploit the class division that exists between rich and poor in other cities. They will do so by promising the wealth, power, or even citizens themselves, of one class to the other in the event of victory, thereby pitting one side against the other (“divide and conquer”). These advantages, Socrates argues, make Kallipolis an unconquerable enemy and an irresistible ally.

While it is tempting to interpret Adeimantus’ question as implying a need that is solely defensive in nature, there is reason to believe that in fact Kallipolis will become compelled to wage offensive war with its neighbors. In Book II (373d-e), Socrates emphasizes that Kallipolis will demand ever more human and natural resources, particularly land, in order to accommodate its growth. In the course of this discussion, Socrates claims that finite land holdings will inevitably cause dissension, as more and more people vie over ever scarcer plots of land. This is the origin of war. The fact of war now requires a standing army for the city’s protection, thereby further increasing the size of the city. Thus, a warrior class emerges – the Guardians – that can furnish adequate security and wage war, both defensive and offensive, on behalf of the state.