What happens without the New START Treaty?

New Deep Cuts publication by Steven Pifer, Patricia Jaworek and Victor Mizin

Der New START-Vertrag ist der letzte noch verbliebene Rüstungskontrollvertrag zwischen den Vereinigten Staaten und Russland zur Begrenzung von strategischen Atomwaffen. Auch dieses Abkommen hat der russische Präsident Wladimir The New START Treaty is the last remaining nuclear arms limitation treaty between the United States and the Russian Federation - and even that was suspended in February 2023 by Vladimir Putin in February 2023.

The consequences of the suspension are still limited, as both sides are complying with the numerical limits on nuclear warheads and delivery systems agreed in the treaty. However, both parties have stopped reporting on their nuclear capabilities as part of the suspension and there is no prospect of a resumption of mutual inspections.  

As a result, the ability of both sides to reliably monitor each other's deployed strategic warheads has been severely weakened. It is true that delivery systems such as intercontinental missiles and bombers can also be counted quite reliably by military reconnaissance. However, it is almost impossible to determine how many nuclear warheads are mounted on a carrier system without an inspection. If one side or the other loses confidence that the other side will comply with the New START ceiling for deployed strategic warheads, pressure could grow to formally terminate the treaty and significantly increase the number of its own strategic warheads.

In the longer term, exceeding the New START Treaty ceilings for deployed strategic warheads and strategic delivery systems could trigger a strategic arms race between the United States, Russia and China that would be difficult to stop. Both treaty parties (including the European states) have an interest in avoiding this scenario.

The full issue brief can be downloaded here.