To solve these problems one needs as much an understanding of politics as an understanding of man - and the one cannot be derived from the other. - Kenneth Waltz

Each state pursues its own interest's, however defined, in ways it judges best. Force is a means of achieving the external ends of states because there exists no consistent, reliable process of reconciling the conflicts of interest that inevitably arise among similar units in a condition of anarchy.

It is not true that were the Soviet Union to disappear the remaining states could easily live in peace.

If we gather more and more data and establish more and more associations, however, we will not finally find that we know something. We will simply end up having more and more data and larger sets of correlations.