This data collection contains a revised version of the Simple Diplomatic Game, one of the first all-computer simulations in the international relations field developed by Oliver Benson in 1959. It represents an early attempt to articulate a number of "loose" assumptions about international behavior into a set of computer instructions such that high-speed computing equipment can be used to simulate a variety of international crises situations. The earlier computer simulation program is reconstructed in this study for 25 nations in 1965 for the purpose of examining the advantages and disadvantages inherent in these simulations and gauging what might be expected of computer simulation methodology in general. The main data matrix contains nine categories of indicators of natural and technical resources used in computing the war potential of each nation, values for nine indicators of aggressiveness used for computing the propensity-to-act index, a numeric code (0-4) indicating alliance membership, a one or zero indicating the nuclear or non-nuclear status of each country, a tally of losses suffered by each coalition member as a result of an unsuccessful initiative on the part of the coalition leader, a statistic for total exports and imports for each country, degrees of longitude for a major industrial area in each country, and degrees of latitude for these industrial areas. Benson's simulation is reprogrammed in this collection in BASIC computer language for use in an on-line, time-sharing environment. Seven additional nations were added and the database for all nations was updated.