The Long Cycle of Global War and the Transformation of Alliance Norms

Within the study of world politics, the relationship between alliance formation and war remains one of the most perplexing problems. This paper contends that explanations of the linkage can be improved by inspection of the effects of global war on changes in the degree to which alliance norms support or reject binding treaty obligations. A macro indicator of alliance commitments is devised that is anchored in international law, and a longitudinal analysis of temporal variations in this indicator in the aftermath of global wars is conducted. Two hypotheses regarding changes in the content of alliance norms are derived from Modelski's well-known theory of the long cycle of world leadership, and are tested through focused comparisons of discrete historical systems. The results suggest that in the 19th century flexible conceptions of alliance commitments tended to predominate in the wake of global war. However, the evidence also suggests that in the aftermath of 20th-century global wars a secular trend toward support for binding conceptions of treaty commitments has prevailed. The historical patterns and permutations within alliance norms observed are evaluated in terms of their implications for cyclical theories of global change.