Exploring the Role Nuclear Weapon's Could Play in Deterring Russian Threats to the Baltic States

xvii, [1], 133, [1] pages. Footnotes. Figures. Tables. Appendices. References. Minor cover soiling noted. 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. 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. 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 military value despite Russian quantitative escalation dominance? What options exist for geographically horizontal escalation and for escalation into other domains? 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 s.…