Countries that formerly had nuclear weapons or have pursued development of nuclear weapons
There are a few countries that either possess nuclear warheads or are very determined to obtain them. But how many of the countries can you name that either once possessed weapons or sought to develop them and since abandoned the idea?
Red = known to have possessed (or possesses) fully functioning nukes
Green = developed programmes far enough to have enriched uranium, or reached other high stage of development
Purple = pursued a research programme but never developed any real tangible resources
Blue = only suspected to seek nuclear capabilities