The Full Form of LTBT is‍ Limited Test Ban Treaty.

The Test Ban Treaty of 1963 prohibits nuclear weapons tests “or any other nuclear explosion” in the atmosphere, in outer space, and under water. While not banning tests underground, the Treaty does prohibit nuclear explosions in this environment if they cause “radioactive debris to be present outside the territorial limits of the State under whose jurisdiction or control” the explosions were conducted. In accepting limitations on testing, the nuclear powers accepted as a common goal “an end to the contamination of man’s environment by radioactive substances.”

Efforts to achieve a test ban agreement had extended over eight years. They involved complex technical problems of verification and the difficulties of reconciling deep-seated differences in approach to arms control and security. The uneven progress of the negotiations reflected, moreover, contemporaneous fluctuations in East-West political relationships.

Prior to SALT, no arms control measure since World War II had enlisted so intensely the sustained interest of the international community. The United States in November 1952, and the Soviet Union in August of the following year, exploded their first hydrogen devices, and rising concern about radioactive fallout and the prospect of even more powerful explosions spurred efforts to halt testing. Succeeding events gave the dangers of fallout concrete and human meaning. In March 1954 the United States exploded an experimental thermonuclear device at Bikini atoll, expected to have the power of eight million tons of TNT. The actual yield was almost double that predicted, about 15 megatons, and the area of dangerous fallout greatly exceeded original estimates. A Japanese fishing vessel, the Lucky Dragon, was accidentally contaminated, and its crew suffered from radiation sickness, as did the inhabitants of an atoll in the area. In another such accident, radioactive rain containing debris from a Soviet hydrogen bomb test fell on Japan.

As knowledge of the nature and effects of fallout increased, and as it became apparent that no region was untouched by radioactive debris, the issue of continued nuclear tests drew widened and intensified public attention. Apprehension was expressed about the possibility of a cumulative contamination of the environment and of resultant genetic damage.

Efforts to negotiate an international agreement to end nuclear tests began in the Subcommittee of Five (the United States, the United Kingdom, Canada, France, and the Soviet Union) of the UN Disarmament Commission in May 1955, when the Soviet Union included discontinuance of weapons tests in its proposals.

Public interest in the course of the negotiations was active and sustained. In individual statements and proposals, and in international meetings, governments pressed for discontinuance of nuclear tests. A dozen resolutions of the General Assembly addressed the issue, repeatedly urging conclusion of an agreement to ban tests under a system of international controls.