Putin said Moscow was not withdrawing from the treaty and would conduct nuclear arms tests only if Washington did so. New START compliance is now explicitly wrapped into the Russian narrative of existential struggle. Both create unpredictable risks of escalation, and that is clearly Putin's intended message on the first anniversary of his unsuccessful war.
Russian military reverses could be the trigger for a tactical nuclear strike, but there is no clear threshold.
New START suspension will encourage hawks such as former Prime Minister Dmitry Medvedev to justify, even advocate nuclear strikes.
A new nuclear arms race would be destabilising and costly, especially for Moscow.
Other would-be nuclear powers, particularly Iran and North Korea, may be emboldened if this part of arms control architecture is dismantled.
