Russia has the capability of advanced nuclear weapons, NKorea has been testing nuclear weapons since 2006 and Iran probably could produce nuclear weapons. The question is whether Russia has thought about helping them, which may be a consideration in the limited use of US-licensed long-range weapons in Russia
If at all possible Iran should be kept in the Non-Proliferation Treaty (NPT), which ensures International Atomic Energy Agency (IAEA) inspections of their facilities. The difficulty is that Iran withdrew authority from some IAEA inspectors which limited inspections and could withdraw from the NPT altogether
Ukraine has also been embroiled in talk of domestic nuclear weapon production this week. President Zelenskyy’s comments provoked a response from President Putin.
The context was that Ukraine would prefer to be in NATO than to have the nuclear weapons that they gave up forty years ago because that’s a stronger option for them, “Zelenskyy later clarified his remarks, stating that Ukraine has no plans to develop nuclear weapons and sees NATO as the only alternative to ensuring its security.” https://www.pravda.com.ua/eng/news/2024/10/18/7480311/
Ukraine is considering using excess manufacturing capability to export weapons to its allies, which would give them money to buy more domestically-produced weapons, “Ukraine’s defence companies can produce $20 billion of weapons and ammunition per year, but Kyiv can only afford to spend $6 billion, the National Association of Ukrainian Defence Industries said” https://www.reuters.com/world/europe/ukraine-work-proposals-possible-weapons-exports-zelenskiy-says-2024-10-18/