Despite its global advantages, the North Atlantic Treaty Organization (NATO)'s current deterrent posture in the Baltic states is militarily weak and generally questionable. A Russian invasion there would almost surely capture some or all of those states' capital cities within a few days, presenting NATO with a fait accompli. This report examines what role nonstrategic nuclear weapons could play in deterring such an invasion.
Exploring the Role Nuclear Weapons Could Play in Deterring Russian Threats to the Baltic States
- What role could the use of nonstrategic nuclear weapons play in deterring Russian aggression in the Baltic states?
- What military and other outcomes would nuclear use accomplish?
- What are the implications for credibly enhancing extended deterrence?
Despite its global advantages, the North Atlantic Treaty Organization (NATO)'s current deterrent posture in the Baltic states is militarily weak and generally questionable. A Russian invasion there would almost surely capture some or all of those states' capital cities within a few days, presenting NATO with a fait accompli. The United States is currently considering tailored deterrence strategies, including options to use nuclear weapons to deter Russian aggression in the Baltic states. This report examines what role nonstrategic nuclear weapons could play in deterring such an invasion. As part of that analysis, the authors review relevant deterrence theory and current NATO and Russian nuclear and conventional force postures in Europe. They draw on wargame exercises and qualitative modeling to characterize the potential outcomes if NATO, Russia, or both employ nonstrategic nuclear weapons during a war in the Baltic states. The authors then discuss implications for using such weapons to deter a Russian invasion. The insights derived from the research highlight the reality that, even if NATO makes significant efforts to modernize its nonstrategic nuclear weapons, it would have much stronger military incentives to end a future war than Russia would. That is, Russia would still enjoy escalation dominance.
- The do-nothing option is very risky: NATO's current deterrent in the Baltic states is militarily weak and generally questionable.
- Improvements to conventional forces have the highest priority; they could also enhance the value of some nuclear options. Some of these improvements are underway.
- Practiced options for extremely fast response without much strategic warning are important because Russia might otherwise find ways, using deception, to accomplish a short-warning fait accompli.
- Despite Russia's regional escalation dominance, the modernized nuclear options might be valuable in certain circumstances of crisis or conflict if Russian leaders have not already anticipated and discounted the significance of NATO's nuclear use (whether a first use or in response to Russian first use).
- Given the limited military value for modernized NATO nonstrategic nuclear weapons, some may question the priority of pursuing such modernization. However, modernized nuclear options would reduce Russian asymmetries in theater-nuclear matters, which can be significant to public and international perceptions. Also, reducing nonstrategic nuclear weapon asymmetries might cause NATO allies to feel more assured of the credibility of U.S. security guarantees and might improve U.S. leverage in possible negotiations about nonstrategic nuclear weapons (the United States has very little leverage now). Finally, modernized nuclear options might be necessary for dealing with security challenges other than Russia.
- To achieve deterrence-favorable conditions, NATO would need to consider substantially enhancing and improving its conventional forces based in and near the Baltic states; fielding some limited nonstrategic nuclear weapons feasible for use throughout a conflict, including very early in the conflict; and going through the lengthy and difficult political and military peacetime processes necessary to make prompt response to warnings feasible and credible.
- Many topics related to deterring Russian aggression in the Baltic states merit further study, such as the following: What would be an action plan to develop and practice rapid-decision and rapid-action processes to prevent a surprise fait accompli despite major deception operations by Russia (e.g., using exercises to cover preparations for invasion)? How would wargaming results change if the initiating scenario resembled the little green men (masked soldiers in unmarked uniforms) employed by Russia in Ukraine in 2014? Are there ways that limited nuclear use by NATO could be given significant (although not decisive) military value despite Russian quantitative escalation dominance? What options exist for geographically horizontal escalation and for escalation into other domains, such as the cyber realm?
Table of Contents
Selective Review of Deterrence Theory
Developments Since the Cold War
Limited Nuclear Options for NATO Consideration
Selected Methods for Evaluating Deterrence Options
Wargaming the Use of Nonstrategic Nuclear Weapons During an Invasion of the Baltic States
A Deterrence Model for Exploring Issues Speculatively
Format for Wargaming a Conflict in the Baltic States
Conventional Force Cost Estimates
Tactical Nuclear Force Cost Estimates