Concurrent interstate conflict simulations: Testing the effects of the serial assumption

The interstate conflict simulation model of Bremer and Mihalka, as extended by Cusack and Stoll, is reimplemented in a massively parallel computational environment. By observing the impact of controlling parameters upon pluralism in simulated state systems, Cusack and Stoll investigate the consequences of competing propositions of the realist school of international relations theory. The simulation method avoids reliance on the highly unrealistic simplifying assumptions characteristic of deductive assessments of realism. However, their simulation model relies on the serial assumption: that only one conflict can occur at one time. The massively parallel implementation removes this assumption, simulating multiple conflicts concurrently. While some minor differences across the serial and parallel implementations are observed at the system level, sharper differences appear in the survival probabilities of states adopting particular styles of decisionmaking. Additionally, relaxation of the Cusack-Stoll assumption that states misperceive others' capabilities at a constant rate of error produces substantial effects at the level of system endurance.