almost anyone that can get the materials
To get nuclear weapons, you must build the Manhattan Project.
All the facilities used by the US to prepare the materials for nuclear weapons, build nuclear weapons, design and test new nuclear weapons. This is all lead by the Department Of Energy.
no
stockpiling
either a build up of nuclear weapons, or a buildup in conventional weapons
North Korea already has the nuclear weapons, it is delivery vehicles it is developing.
Your questions asks for an opinion. My opinion is no. The knowledge of how to build a nuclear weapon is out there. There are too many people with different views and values for nuclear weapons to just go away.
Nuclear weapons in the US are all refurbished at PANTEX just east of Amarillo, TX. No new nuclear weapons are built at this time by the US.
Japan doesn't want any nuclear weapons.But Japan can easily produce nuclear weapons if it wanted to. It has the technology to build nuclear weapons within 1 year-- probably a few months if it wanted.However, most Japanese people are against nuclear weapons. Therefore, they do not have nuclear weapons.
Nuclear arms race.
Mutually assured destruction, called for short (and sensibly so): the M.A.D. Principle.
The human mind creates them, then factories build them... like everything else.