The Treaty on the Non-Proliferation of Nuclear Weapons is an international agreement to limit the spread of nuclear weapons. It was originally signed by the US, Britain, the USSR, and 59 other countries in 1968. The major signatories agreed not to help nonnuclear states obtain or produce nuclear weapons, while the nonnuclear signatories agreed not to try to obtain them. The treaty was extended indefinitely in 1995, and nearly 190 countries are now party to it. Which nations have never signed it? Discuss...
Nuclear Non-Proliferation Treaty (1968) (http://encyclopedia.thefreedictionary.com/Nuclear+non-proliferation+treaty)