The Comprehensive Nuclear Test Ban Treaty

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans nuclear explosions by everyone, everywhere: on the Earth's surface, in the atmosphere, underwater and underground for military and civilian purposes.Ones the treaty is ratified by a nation,it makes it very difficult for that country to develop nuclear bombs for the first time, or for countries that already have them, to make more powerful bombs.

The Treaty was adopted by the United Nations General Assembly on 10 September 1996 and signed by 71 States, including five of the eight then nuclear-capable states.
Latest status on CTBT
Total states : 195
Total signed : 182
Total ratified : 154
Not signed : 13
Latest signed country : Trinidad & Tobago (Oct 2009)
Latest ratified country : Ghana (June 2011)

182 countries have signed the Treaty, of which 154 have also ratified it (as of June 2011),including three of the nuclear weapon States: France, Russia and the United Kingdom. But 44 specific nuclear technology holder countries must sign and ratify before the CTBT can enter into force. Of these, nine are still missing: China, Egypt, India, Indonesia, Iran, Israel, North Korea, Pakistan and the USA. India, North Korea and Pakistan have yet to sign the CTBT. Indonesia announced that it had initiated the ratification process in May 2010. Since the Treaty is not yet in force, the organization is called the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Organization (CTBTO). It headquarters is based in Vienna.

The Treaty has a unique and comprehensive verification regime to make sure that no nuclear explosion goes undetected. This regime consists of three pillars:
1. The International Monitoring System (IMS) will, when complete, consist of 337 facilities worldwide to monitor the planet for signs of nuclear explosions.
2. The International Data Centre at the CTBTO’s headquarters in Vienna receives the data from the global monitoring stations.
3. On-site inspections can be dispatched to the area of a suspicious nuclear explosion if the data from the IMS indicate that a nuclear test has taken place there.
The data collected by CTBTO can be used for another purposes like tsunami warnings, understand the oceans, volcanoes, climate change, the movement of whales etc.