The economist notes that there are believed to be six so-called threshold countries that could build nukes relatively quickly: Turkiye, Brazil, South Korea, Japan, Saudi Arabia, and Iran.
Poland has signaled nuclear ambitions, he adds, and other countries “also have the technological and financial capabilities,” says Professor Dynkin.
Under New START, which expired on February 5, the US and Russia had mutually adhered to caps of 1,550 deployed strategic nuclear warheads and 700 deployed delivery vehicles (ICBMs, SLBMs, and heavy bombers), plus 800 total launchers and bombers.
The US rejected Russia's proposal for a one-year voluntary extension, arguing instead for negotiations on a new, modernized arms control agreement.