Open sea nuclear tests are banned by the Limited Test Ban Treaty (LTBT), which was signed in 1963. This treaty prohibits nuclear weapon tests in the atmosphere, outer space, and underwater, including in territorial waters and the high seas. The treaty was a significant step in limiting the spread of radioactive fallout and promoting international cooperation on arms control.
The CTBT, agreed in 1996, bans "any nuclear weapon test explosion or any other nuclear explosion" anywhere in the world, with the goal of reducing and ultimately eliminating nuclear weapons. Its preamble says it is aimed at supporting disarmament and non-proliferation by constraining the development of nuclear weapons and stopping countries producing more advanced ones.
The
Partial Test Ban Treaty (
PTBT), formally known as the 1963
Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water, prohibited all
test detonations of
nuclear weapons except for those conducted
underground. It is also abbreviated as the
Limited Test Ban Treaty (
LTBT) and
Nuclear Test Ban Treaty (
NTBT), though the latter may also refer to the
Comprehensive Nuclear-Test-Ban Treaty (CTBT), which succeeded the PTBT for ratifying parties.