We are often asked which countries have nuclear weapons, are seeking them, or may seek them in the future. In trying to answer the question, we have had to consider which countries possessed or tried to obtain nuclear weapons in the past. Our findings about both current and historical nuclear weapons programs are outlined on an interactive world map, and summarized in a companion table.

South Korea had a nuclear weapons program which ended after 1970.  In 2004, South Korea disclosed that it had secretly conducted a plutonium-based nuclear experiment in 1982 and a uranium enrichment project in 2000.