But by the end of the 1980s, the Cold War was winding down, major changes were beginning to take place within the Soviet Union, and the absurd redundancies of accumulated nuclear capabilities became obvious to the ruling elite on both sides. That created a powerful impetus for negotiations on the deep reduction of nuclear weapons, culminating in radical treaties, such as the INF Treaty in 1987 and the first Strategic Arms Reduction Treaty (START 1) in 1991. Against this favorable backdrop, the concept of strategic stability became a legal norm.
That concept was formally invoked for the first and, unfortunately, last time in June 1990 in the Soviet-United States Joint Statement on Future Negotiations on Nuclear and Space Arms and Further Enhancing Strategic Stability.8 The concept was defined as a strategic relationship that eliminates the “incentives for a first nuclear strike.”9 To create this kind of relationship, future agreements on strategic arms limitations were to include a number of agreed-upon elements:
“the relationship between strategic offensive and defensive arms” (so that defenses cannot undermine the other side’s ability to retaliate);
“measures that reduce the concentration of warheads on strategic delivery vehicles” (so one missile armed with several warheads could not hit several enemy missiles at their bases carrying a much larger number of warheads); and
“giving priority to highly survivable systems” (so that they cannot be destroyed before launching a retaliatory strike).
This concept radically revised conventional wisdom. During the Cold War, each side ideologically perceived the enemy as an imminent aggressor, regardless of the specific content of its military doctrine or composition of its weapons arsenals. Now, both sides subscribed to the premise that a first nuclear strike is an act of aggression, no matter which state committed it. The basic assumption was that the goal of a first strike was to prevent or substantially weaken the retaliatory potential of the enemy by defeating its strategic forces at their starting positions, and to mitigate the impact of surviving weapons with ballistic missile defenses (BMD).
Strategic nuclear forces10 were therefore excluded, by default, from the military theorist Carl von Clausewitz’s immortal formulation, “War is the continuation of politics by other means.” According to the logic of the 1990 Joint Statement, if neither party is able to significantly reduce the damage of the other’s retaliatory strike by launching a first strike, then the outbreak of war (the first strike) will not be a continuation of politics by other means, even in the event of an acute conflict of interest between the two states.
It is important to emphasize that the content of strategic stability was agreed upon during the negotiations for START I, signed in 1991, the complex provisions of which embodied all the principles of this concept. These were subsequently reflected in the 1993 START II, the 1997 START III Framework Agreement, the 2002 Strategic Offensive Reductions Treaty (SORT), and New START. As major parallel measures, deep parallel reductions were conducted regarding tactical nuclear arms, negotiations to conclude a treaty banning the production of fissile materials for military purposes (Fissile Material Cutoff Treaty) began in 1993, and the Comprehensive Nuclear-Test-Ban Treaty (CTBT) was signed in 1996.
As a result of the implementation of these agreements, today’s strategic balance looks much more stable (according to the criteria agreed upon in 1990) than on the eve of the 1990s, that is, before the signing of START I. The permitted levels of strategic weapons have been reduced about sixfold for warheads, almost threefold for deployed delivery systems, and by about thirtyfold for total megatonnage.11 The ratio of warheads to delivery systems has decreased from 5:1 to 2:1. The share of arms with increased survivability,12 which once stood at 30–40 percent, now amounts to 60–70 percent of the Russian and U.S. strategic nuclear arsenals.
Even more importantly, the strategic balance has become much more stable in substance—in terms of its 1990 definition, that is, the elimination of incentives for a nuclear first strike. Models of a hypothetical nuclear exchange show that, under realistic conditions, an attack by either party is not capable of destroying more than 50 percent of the other side’s forces while employing 20 percent more weapons than are hit.13 In other words, an aggressor would disarm himself in a first strike, and the party under attack would have more surviving nuclear forces than the aggressor has in reserve after the strike, and could strike back, depriving the initiator of the desired advantage of the first strike.
Nevertheless, strategic stability as one of the models of mutual nuclear deterrence is now deteriorating due to the evolution of strategic concepts and operational plans on both sides, as well as the beginning of a large-scale cycle of nuclear and advanced conventional arms races. These processes are naturally exacerbated by what is essentially a new Cold War between Russia and the West, which has accelerated the collapse of nuclear arms control.
Modern Nuclear Doctrines
The role of nuclear weapons in Russia’s foreign and military policy has increased markedly since 2011, following the ratification of New START and the failure of dialogue between the United States and Russia on the joint development of missile defense systems. Ahead of his victory in Russia’s 2012 presidential election, Vladimir Putin stressed: “Under no circumstances will we give up the potential of strategic deterrence, and we will strengthen it. So long as the ‘powder’ of our strategic nuclear forces, created by the great effort of our fathers and grandfathers, remains ‘dry,’ no one will dare unleash large-scale aggression against us.”14 This policy implied the large program of modernizing strategic nuclear forces, including the deployment of 400 new intercontinental ballistic missiles and the construction of eight nuclear-powered ballistic missile submarines.15
Meanwhile, U.S. President Donald Trump said in 2017: “Let it be an arms race. We will outmatch them at every pass and outlast them all.”16 The position of the current U.S. political and military leadership on all aspects of nuclear deterrence is laid out quite clearly in the Nuclear Posture Review, published in January 2018. It is immediately apparent that in its basic assumptions, this policy is in tune with the Russian approach: “A safe, secure, and effective nuclear deterrent is there to ensure that a war can never be won and it will never occur.”17 But the analogies do not end there. Both powers embrace not only retaliatory strikes in the event of an attack using nuclear weapons, but also their first use in response to an attack using conventional forces, as well as in some other situations.
The 2018 Nuclear Posture Review emphasizes: “Given the diverse threats and profound uncertainties of the current and future threat environment, U.S. nuclear forces play the following critical roles in U.S. national security strategy. They contribute to the deterrence of nuclear and non-nuclear attack; assurance of allies and partners; achievement of U.S. objectives if deterrence fails; and capacity to hedge against an uncertain future.”18 The Russian military doctrine, published in 2014, also calls for “permanent readiness of the Armed Forces, other troops, and bodies for