START III, or the Strategic Arms Reduction Treaty III, was a proposed agreement aimed at further reducing the number of nuclear weapons held by the United States and Russia. Following the earlier treaties, START I and START II, it sought to limit deployed strategic warheads and delivery systems, enhancing global security. Negotiations for START III began in the late 1990s but faced challenges due to differing priorities and geopolitical tensions. Although the treaty was never finalized, it highlighted the ongoing dialogue between the two nations regarding nuclear disarmament and arms control, reflecting the complexities of international relations in the post-Cold War era.