Seabed Treaty Signed: Nuclear Weapons Banned from Oceans

Eighty-seven nations signed the Seabed Arms Control Treaty on February 11, 1971, prohibiting the placement of nuclear weapons or other weapons of mass destruction on the ocean floor beyond each country's twelve-mile territorial limit. The treaty closed a dangerous gap in the arms control architecture: existing agreements covered atmospheric testing and outer space, but nothing prevented nations from hiding nuclear weapons beneath international waters. The seabed represented two-thirds of Earth's surface, and advances in submarine and deep-sea technology were making the deployment of seabed weapons increasingly feasible. The Soviet Union and United States both signed, recognizing that an underwater arms race would be prohibitively expensive and destabilizing. France and China, both nuclear powers, declined to sign. The treaty included verification provisions allowing any signatory to observe seabed activities but provided no enforcement mechanism beyond raising concerns with the UN Security Council.