1945 - Atomic bombs are used by the United States against Japan.
1992 - September - The United States conducts its most recent nuclear test, "Divider."
1992 - October - U.S. imposes restrictions on nuclear testing, Russia extends test moratorium
1993 - April - U.S. President Clinton and Russian President Yeltsin agreed to begin negotiations on multilateral test ban
1993 - August - Conference on Disarmament mandates its Ad Hoc Committee on a Nuclear Test Ban to negotiate a CTBT
1993 - October - China conducts a nuclear test.
February 1994 - Negotiations on a comprehensive nuclear-test-ban treaty begin in the Conference on Disarmament.
1994 - June - China conducts an underground nuclear test.
1994 - October - China conducts an underground nucear test.
1995 - January - President Clinton says in State of Union: "The United States will lead the charge to extend indefinitely the Nuclear Non-Proliferation Treaty [and] to enact a comprehensive nuclear test ban."
1995 - May - China conducts a nuclear test
1995 - June - France announces it will conduct 8 nuclear tests in the next year
1995 - August - France announces once it is done testing, it would support a CTBT
1995 - August - China conducts a nuclear test
1996 - April - Russia endorses a zero-yield CTBT and reserves the right to resume testing if Russia's supreme interests are in jeopardy. The Group of 7 and Russia pledge to sign a CTBT by September 1996.
1996 - June - India states it will not sign a CTBT unless the five declared nuclear weapon states agree to give up their nuclear weapons
1996 - July - U.S. and Russia announce joint support for the existing draft CTBT, though it did not fully satisfy each nation.
1996 - August - China and U.S. reach agreement on modifying treaty text to resolve China's concerns over verification.
1996 - August - India vetoes draft CTBT in CD, barring the treaty from going to the United Nations as a CD document
1996 - August - Australia asks UN General Assembly to begin consideration of the draft CTBT
1996 - September - UN General Assembly adopts the CTBT by a vote of 158-3-5
1996 - September - President Clinton and other world leaders sign CTBT
1996 - November - CTBT Preparatory Commission meets for the first time
1998 - April - France and Great Britain are the first declared nuclear weapons states to ratify the CTBT
1998 - May - India conducts five nuclear tests
1998 - May - Pakistan conducts six nuclear tests.
1999 - October - US Senate rejects CTBT by a vote of 48-51-1
2001 - November - Conference on Facilitating the Entry-Into-Force of the CTBT begins at UN headquarters
2005 - Sept - Conference on Facilitating the Entry-Into-Force of the CTBT is held at the UN headquarters
Sources:
"Nuclear Testing and Comprehensive Test Ban: Chronology Starting September 1992." CRS Report for Congress. 31 Aug 2005. 28 Feb 2006. <http://www.cnie.org/nle/crsreports/05aug/97-1007.pdf>
"Timeline." Atomic Weapons Establishment. 28 Feb 2006. <http://www.awe.co.uk/main_site/about_awe/history/timeline/>