The majority of countries in the world—the non-nuclear-weapon states (NNWS) — are committed to remaining free of nuclear weapons, including some countries that once possessed nuclear weapons. South Africa announced in July 1993 that it had developed a small arsenal before destroying it in 1991 in order to join the NPT as a NNWS. Belarus, Kazakhstan, and Ukraine returned large arsenals of nuclear warheads and associated delivery systems inherited from the former Soviet Union to Russia in the mid-1990s, subsequently joining the NPT as NNWS.