The screaming nail the coffin was our reaction to Ukraine, where Russia’s nukes dominated the conversation, versus Iran, where their non-existent nukes did not. Ukraine was proven stupid trading its nukes for empty promises. The world saw and learned.
It remains to be seen what will happen with lesser ones. The entire world combined has fewer than a third of either the Russian or American arsenals (by number of weapons).
https://en.wikipedia.org/wiki/List_of_states_with_nuclear_we...
Proliferation is also about vaccination and HIV prevention, etc. USAID et al. are among the most important programs in development and prevention worldwide. This is a tragedy chosen by a majority of Americans because what goes around comes around. COVID showed again that pandemics don't stop at borders.