The concept of mutual nuclear deterrence between the United States and the Soviet Union/Russia, which accompanied and outlasted the Cold War, is likely to remain in place in the foreseeable future. Up until now, the two states have been able to maintain the balance in their deterrence capabilities through a series of bilateral agreements; however, this balance can easily become upset if the New START Treaty expires and no follow-on agreement is reached. It can either cause the United States and Russia to focus on developing new types of strategic nuclear weapons and making qualitative improvements in the existing weapons systems instead of furiously building up their nuclear arsenals, or result in the United States increasing the number of its strategic nuclear weapons (for example, through multiplying warheads on their ICBMs and SLBMs). At the same time, Russian nuclear deterrence capabilities, according to the estimation results, will remain at the level that would rule out any incentives to launch a first strike against it. The US anti-ballistic missile systems and high-precision conventional weapons would have little to no impact on Russia’s second-strike nuclear capability. However, they will have the potential to set off a new nuclear arms race and destabilize the entire international nuclear nonproliferation regime. It might be possible to avoid the worst-case scenario by extending the New START Treaty and starting negotiations on a follow-on treaty in the near future; however, while US President Donald Trump and his administration ’s international security policy leaves open some possibility for New START extension and negotiations of new strategic arms control agreements, their persistent demands to include China in the talks to replace New START effectively nips this possibility in the bud. The current situation might evolve as a result of a change in the US administration. In such case, various conditions for strategic arms control negotiations could be considered. The emergence of Russian missile systems Sarmat and Avangard does not technically serve as a limiting factor for the extension of the New START, as well as for negotiations on a follow-on treaty. On the other hand, the inclusion of Poseidon and Burevestnik systems in a new arms control treaty shall present a daunting challenge. Scenarios for a nuclear exchange are based on the idea that a retaliatory strike is launched within a very short time after the first strike is carried out by an aggressor. The Russian triad of strategic nuclear forces, the way it exists now and after its modernization, is and will be able to provide assured nuclear deterrence against the United States without the help of new weapons systems such as Poseidon and Burevestnik. These weapon systems do not fit into plausible nuclear exchange scenarios, and therefore provide no valuable contribution to them. If these new systems present obstacles to the successful negotiation of a follow-on START treaty and create a risk of a nuclear arms race, it will be appropriate to freeze their further development, while also maintaining the groundwork that has been laid for their research and production for contingency reasons.