Nuclear Weapons and International Conflict: Theories and Empirical Evidence

Abstract The balance of conventional military capabilities is intrinsic to understanding patterns of war among nations. However, cumulative knowledge relating to the effects of nuclear weapons possession on conflict interaction is largely absent. Framework is provided for analyzing the results of quantitative empirical research on this question and to identify any extant strong and consistent patterns in the interactions of states that can be associated with the possession of nuclear weapons. Since 1945, a vast, sophisticated, and contradictory literature has developed on the implications of nuclear weaponry for patterns of international conflict and war. This theoretical and empirical work has principally focused on the conflict effects of these weapons for the interaction of nuclear-armed states, although a growing number of studies have explored the impact of a state’s possession of nuclear weapons on the behavior of nonnuclear opponents. Given the destructive capacity of these weapons and their questionable value for battlefield use, most of this work has concentrated on the requirements for successful deterrence. In categorizing the studies, some scholars note that “classical deterrence theory” derives from the Realist paradigm of international politics and subdivide this theory into two complementary strands: structural (or neorealist) deterrence theory and decision-theoretic deterrence theory. In contrast, other analysts choose to classify work on nuclear deterrence into three schools of thought: nuclear irrelevance; risk manipulation, escalation, and limited war; and the nuclear revolution. The essence of these divisions involves a debate about what the possession of nuclear weapons does for a state that controls them. Does the possession of these weapons affect the behavior of nuclear and nonnuclear opponents in disputes over contested values? Do the weapons impart political influence and hold military utility, or are they useless as tools for deterrence, compellence, or war?