This overview of the technical and political dimensions of nuclear non-proliferation aims to guide the student of arms control through the fundamentals of nuclear physics, nuclear reactors and the nuclear fuel cycle in language familiar to any interested reader. He likewise explains clearly the evaluation of the nuclear non-proliferation regime, the system of international nuclear safeguards and the prospects for the extension of NPT in 1995. The primer includes information on the status of nuclear programmes in the nations of greatest proliferation concern, a glossary and the full text of the NPT.