Multipolar Nuclear Stability: Incentives to Strike and Incentives to Preempt

Abstract

This paper considers three armed sides and one unarmed side. All four sides have value targets and all four sides may have defenses. The paper proposes a concise, parsimonious theory of multipolar nuclear stability, with two measures -- incentive to strike and incentive to preempt.

The objective of this paper is to present a framework with the minimal number of dimensions required to describe the problem, which turns out to involve sixteen resource and attrition parameters. Together with behavioral assumptions about the fighting of twelve possible wars -- six with three sides acting separately and six with three sides organized into two coalitions -- the sixteen dimensions are mapped onto measures of incentive to strike and incentive to preempt. The framework is abstract but the qualitative insights are logically persuasive.

An example is given addressing the stability of START II and beyond strategic force structures. The sides are (1) United States/Britain/France, (2) Russia, (3) China with a larger arsenal and (4) “Rest of the World”. Two other scenarios have also been analyzed within the same framework:

• a. Mideast Scenario. How do deployable tactical missile defenses affect stability among three sides: (1) United States/Western Europe/Mideast Allies, (2) Russia and (3) China/Mideast Allies?

• b. Korea Scenario. What is the regional stability among (1) armed North Korea, (2) armed South Korea, (3) armed China and (4) unarmed Japan? How do defenses affect stability?

One robust conclusion obtained from analyzing multipolar nuclear scenarios with this structure, which is expected to hold for all similar three-sided and four-sided scenarios, is that defenses of two large sides which are large relative to a third small side but small relative to each other are stabilizing. Also, a defense of the fourth, unarmed side which is large relative to the third side but small relative to the first and second sides is stabilizing.