International treaties and agreements are playing an increasing role in promoting international security in an environment where non-military elements are becoming increasingly important. Today efforts to preserve our global environment and to prevent the proliferation of weapons of mass destruction are at the head of the international security agenda. The CTBT is an essential contribution to the global non-proliferation regime and a step towards nuclear disarmament. More than ten years have now passed since the Treaty was opened for signature and it has not yet entered into force for reasons we discuss later. All States Signatories, including those that have not ratified, have declared their intent to renounce further testing. Even though it is not in force, the CTBT has thus established a norm of non-testing among its signatory States, which is politically difficult and costly to break.