The theory of war cycles holds that wars happen in cycles.

The forerunner of the study of war cycles was Edward R Dewey, with Quincy Wright's monumental A Study of War adding impetus to the discipline.^{[citation needed]} The credibility of the study of cycles was frequently questioned,^{[by whom?]} as this type of inquiry attracts persons with marginal credibility and interest in paranormal issues. However, with advent of computer algorithms minimizing the dampening effect affecting the abstracted oscillations and facilitating the detection of stochastic drifts, the study of cycles is subject to renewed interest (see, e.g., *History & Mathematics: Historical Dynamics and Development of Complex Societies / Ed. by Peter Turchin et al.. Moscow: KomKniga, 2006. ISBN 5-484-01002-0).^{[original research?][not in citation given]}

In the judgment of the Nuremberg Tribunal, war of aggression is the supreme crime, and there is hardly any other issue that is more relevant to the social sciences than the study of the decision-making process when a person or a group of persons decides that another group of people must face death.^{[original research?]} Historians^[who?] speculated about this decision-making process for centuries without reaching consensus, as wars are complex phenomena with multiple determinants. The decision to initiate a war marks an inflection point of the war-peace cycle, and the decision to cease hostilities marks the end of a particular cycle.^{[citation needed]} Comparative studies of war cycles can contribute to explication of facets of this decision-making process. Most relevant of these facets are those that help us to identify the preventable factors influencing the decision to initiate (and to terminate) a war.^{[original research?]}