On the Balance of Strategic Nuclear Forces

The development of strategic nuclear forces (SNF) is becoming an increasingly relevant topic in light of the latest United States Nuclear Posture Review and other policy papers, as well as Russia’s announcement regarding the development of new nuclear delivery vehicles. China is also developing its own SNF. To assess the role and place of various types of nuclear weapons in the overall structure of nuclear deterrence, we have developed a simplified model of SNF “interaction” for first, launch-under-attack, and second strikes.

The development of strategic nuclear forces (SNF) is becoming an increasingly relevant topic in light of the latest United States Nuclear Posture Review and other policy papers, as well as Russia’s announcement regarding the development of new nuclear delivery vehicles. China is also developing its own SNF. To assess the role and place of various types of nuclear weapons in the overall structure of nuclear deterrence, we have developed a simplified model of SNF “interaction” for first, launch-under-attack, and second strikes.

As baseline data for our analysis, we used reviews of the world’s nuclear forces by the Federation of American Scientists, as it is the most complete and consistent corpus of materials published on the subject.

The simulation was carried out using conditional “warhead equivalents” with a yield of 100 kilotons in order to provide a comparison of warhead (WH) of different yields. RVs are standardized according to the two-thirds power rule (e=n^(2/3)), as this roughly corresponds to the comparison of the areas (square law) hit by the blast wave (root law of the third degree) of these RVs. In the comparison, we used the total equivalent arsenals on various delivery vehicles and launchers for their “survivable” (extremely likely to survive in the event of an SSBN or mobile ground missile system strike) and “residual” (that which remains after the first RV strike, taking an assessment of technical readiness into account) potentials. In the event that survivable potential is lower than the deterrence criterion or lower than residual potential, the enemy is tempted to use SNF as a first strike, as a subsequent countervalue exchange will be both tolerable and advantageous.

Fig.1

The simulation has shown that a sudden first strike by the United States on Russia would take out up to 86 per cent of Russia’s SNFs in “delivery systems” and 87 per cent in “explosive tonnage”; 13–14 of the 138 ISBMs and missile launch facilities, around 30 mobile ground missile systems and submarine-launched ballistic missiles (of the 180 and 176, respectively), and roughly 10 strategic bombers would survive. Nevertheless, the surviving forces would be sufficient to carry out strikes on all major U.S. cities.

In the event of a sudden first strike by Russia on the United States, 30 percent of the country’s SNFs in “delivery systems” and 44 per cent of its SNFs in “explosive tonnage” would survive, mostly on Ohio-class SSBNs. A more detailed diagram is provided below. 

The tables (Fig. 1 and Fig. 2) show that a launch-under-attack strike on the enemy would cause damage that satisfies all reasonable criteria for deterrence. What is more, a balance would be established between the residual and survivable potentials of the side under attack.

Thus, a comparison of the launch-under-attack strike and deep counter strike scenarios leads us to the conclusion that the latter is less stable from a strategic point of view. The aggressor has a more pronounced advantage in terms of residual potential, especially in the event that the United States delivers the first strike. In this regard, various measures to reduce the readiness of the SNF (de-alerting) would negatively impact the stability.

Fig. 2

Active protection systems for missile launch and other valuable facilities (such Nuclear Command, Control & Communications centres) also have a stabilizing effect by increasing the number of warheads required to destroy them (from two to around ten warheads). This allows for a more stable balance even in the event of a deep second strike. At the same time, the United States would not have any warheads left for SLBMs and ICBMs after the first countervalue strike and would only be able to carry out an air strike.

Fig. 3

Even if the United States were to enlist its NATO allies or, for example, if Russia were to enlist China to take part in the operation, and if strategic weapons were used instead of nuclear weapons, it would still not be possible to ensure the reliable defeat of the SNF forces of either the United States or Russia, assuming that the balance of powers was not altered greatly (through the deployment of hundreds of new combat units, including low-power, non-nuclear, and other combat units).

The question of how the situation between the US and Russia should develop is extremely relevant. Even an extensive discussion of military doctrines between the countries concerned will not lead to a full understanding of what constitutes unacceptable damage. The McNamara/Sakharov criteria of the Cold War period were purely speculative as well, although we can say that they were proven to be sound through empirical practice, as there were no nuclear strikes during that time. The maintenance of strategic stability in the current situation, which is marked by a significantly lower that the Cold War era level of SNF by numbers, paves the way for thinking about further reductions in the future.

The model presented above shows that if the total number of warheads in the US and Russia is reduced to 1000, it would be possible to increase the significance of missile defense and active missile launch protection systems, assuming the ratio of survivable to residual potentials does not shift towards a countervalue exchange following a first strike. There is no need at the moment to discuss an impenetrable nuclear umbrella if we compare the expected number of surviving combat units (around 250 in the case of Russia) for ICBMs and SLBMs with the number of interceptors (40–60 deployed land-based GBI interceptor missiles) that are capable of hitting them, especially in the context of the upcoming deployment of hypersonic glide vehicles (e.g Avangard) and other more exotic delivery methods. However, if the situation is reduced to the delivery of a single warhead, then it might be tempting to use this as a final argument.

The state of strategic nuclear forces during long-term exposure to enemy activity has not been considered, in large part because such a situation seems highly unlikely. Similarly, short-term massive strikes using high-precision weapons were not taken into account due to the current level of development of the Russian Early Warning systems. It is possible to detect in advance a slow strike carried out by a long-range cruise missile (such as the TLAM or JASSM-ER) and stealth bombers (such as the B2A and B21 models). In the future, it may be possible to carry out the “normal” second strike scenario based on data provided by over-the-horizon radar stations.Prompt Global Strike and other similar programs of precision-guided conventional weaponscan be seen as additional incoming warheads. The influence of these systems on the overall SNF balance is insignificant, as there are well-known limitations on the number of existing and planned carriers (e.g. nuclear submarines). Nevertheless, systems such as these are not taken into account in agreements on strategic arms reduction, yet they are essentially strategic arms. This problem is particularly pressing in light of the continued reduction of SNF and their de facto replacement with new unregulated types of strategic arms for the same carriers.

Another (probably more important) line of Russia’s SNF development is increasing the Operational Tempo [1] of SSBNs and road-mobile ICBM launchers, at least for the supposed threat period. This would require the development of general-purpose army and navy forces, as well as the overall improvement (in the broadest sense of the word) of the reliability of weapons and military technology.

As for China, it is clear that the country’s industry is prepared to provide a sharp increase of SNF quantitative indicators. Another constraining factor — in addition to the apparent confidence in the sufficiency of individual warheads, which are guaranteed to be delivered to enemy territory — could be the technical imperfection of available products, as well as doubts about the possibility of providing the necessary conditions for the operational readiness of subsurface launch platforms.

This is an extremely simplified picture, and it would be wise to exchange ideas about the findings in expert circles as part of Track 1.5 diplomacy in order to arrive at a sounder assessment of Russian and U.S. strategic military developments. The simulation instrument that has been created allows us to assess various development scenarios, including from the point of view of ensuring operational readiness and developing new, modernized, and alternative strategic offensive and defensive weapons.

1. Operational Tempo – the ratio of deployed combat units to total combat units.