This work uses two data sets provided through the Inter-university Consortium for Political and Social Research: The Behavioral Correlates of War data were originally collected by Russell J. Leng; the Interstate Security Conflicts data were originally collected by Robert L. Butterworth. I also use a draft version of the COPDAB data set provided by Edward Azar. Neither the original collectors nor the ICPSR bear any responsibility for the analyses or interpretations presented here. The Midwest Consortium for International Security Studies, the NSF-funded Data Development in International Relations project, the NSF-funded Political Methodology summer conferences, and the Austrian Federal Ministry for Science and Research have greatly aided this research through the sponsorship of various conferences; these were facilitated in part by Richard Merritt, Marian Rice, Frank Scioli, Robert Trappl and Dina Zinnes, as well as by many of the individuals named earlier. The research was directly supported at times by National Science Foundation Grants SES89-10738 and SES90-