This term refers to the negotiations between the United States and the Soviet Union/Russian Federation to limit and reduce the numbers of strategic offensive nuclear weapons in each country's nuclear arsenal. The talks resulted in the 1991 START I Treaty, and the 1993 START II Treaty. START I was originally negotiated between the United States and the Soviet Union, and now applies to the United States, Russian Federation, Belarus, Kazakhstan and Ukraine. Belarus, Kazakhstan, and Ukraine have all renounced their possession of nuclear weapons under the 1992 Lisbon Protocol to START I. START II, which calls for further reductions in the United States and Russia has been ratified by the two countries, but has not yet entered into force.

See Lisbon Protocol.