We can now turn to the third part of our study. It will be recalled that we examined the ways in which differentiation of power occurred through ordinary social exchange, and how, in these conditions, mutual fears stimulated perceptions of hostility and defensive responses that were cumulative and self-defeating. Then we modified this first approach by dealing with the other side of exchange relationships, the integrative and cooperative aspects through which groups gain without necessarily loss of independence. We considered aspects of state behaviour and decision-making. It will be recalled that in embarking on this second part a warning was given – not to assume that state behaviour could provide a full explanation or understanding of world society, or, by implication, solutions to world problems. Now we turn to look at world society as a whole and modify our approach and take into account influences outside state control.

We have already seen that ‘national interests’ are frequently expressions of interests of nationals shared by nationals of other states, leading to common policies and functional cooperation within the inter-state system. Can we go further, are there interests held in common universally which would justify our looking at world society as a unit?

This question has two aspects. It may be true that all states have some identical interests and that there are universal interests in the inter-state system; but these interests may be incompatible nevertheless. Each state wants security and prosperity, and it may be that the security and prosperity of one means the insecurity and poverty of another.