I am not saying that such a theory cannot be constructed, but only that I cannot see how to do it in any way that might be useful. The decisive point… - Kenneth Waltz

According to the first image of international relations, the locus of the important causes of war is found in the nature and behavior of man. Wars result from selfishness, from misdirected aggressive impulses, from stupidity.

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.

Differences in the incidence of destruction and "death" do not account for the reluctance to refer to international politics as a harmonious realm, while competitive economies are often so described. Instead, one may say that the standards of performance now applied to international political systems are higher, or at least widely different. As John Maynard Keynes once remarked, those who believe that unhampered processes of natural selection lead to progress do not "count the cost of the struggle" (1926, p. 37). In international politics, we often count nothing but the costs of the struggle.