Its inevitable nations hostile to the US will get nukes. That’s why the US left the ABM treaty even though it knew it would lead to resumption of nuclear arms race. Their rationale is a full out nuclear war with a big player is mutual assured destruction due to the large volume of inbound Mirvs and cruise missiles.. If any small nation with limited nuclear capability wanted to try the same thing though they have a good shot at stopping inbound missles whereas the country launching them would be turned into ash.