June 1 - President Bush and President Gorbachev sign new protocols to the Threshold Test Ban treaty.
September 25 - U.S. ratifies the Threshold Test Ban Treaty.
September 27 - The last Pershing II missile is removed from West Germany
December 11 - The Threshold Test Ban Treaty enters into force.
July 31 - President Bush and President Gorbachev sign the Strategic Arms Reduction Treaty (START). The Treaty calls for the elimination of almost 50 percent of the nuclear warheads carried by ballistic missiles.
December 5 - Bush signs the Missile Defense Act of 1991, which mandates the Department of Defense develop a missile defense system.
Communism falls across Eastern Europe, the Soviet Union is replaced by the Commonwealth of Independent States (C.I.S.).
June 1 - Strategic Air Command (SAC) is deactivated. A new, unified command, STRATCOM (Strategic Command) was activated in its place and controls the nuclear weapons assets of the United States.
The START treaty is ratified by the U.S. Senate.
Kazakhstan, Ukraine, and Belarus agree in principle to the START treaty.
August 3 - France officially signs the Non-Proliferation Treaty.
January 3 - Bush and President Yeltsin sign the Strategic Arms Reduction Treaty (START II), which reduces their nations' arsenals of long-range nuclear weapons to 3,000-3,500 and eliminates all MIRVed land-based missiles over the next ten years.
March - Prime Minister F.W. de Klerk announces that South Africa had successfully developed nuclear weapons, and then voluntarily destroyed them before signing the NPT in 1991.
Attempts to smuggle nuclear material from C.I.S. are stopped.
Secret nuclear testing on humans is revealed by both the U.S. and C.I.S.
North Korea is suspected to be building nuclear weapons; they threaten to withdraw from the IAEA.
May 11 - 178 nations renew the Non-Proliferation Treaty.
May 15 - China conducts an underground nuclear test.
August - President Clinton announces a total ban on all U.S. nuclear weapon testing.
September 5 - France resumes nuclear testing in the South Pacific. A total of six nuclear tests are conducted.
January 29 - French President Chirac announces an end to French nuclear tests.
April 11 - The Treaty of Pelindaba is signed by 49 of the 53 members of the Organization of African Unity. It creates an African nuclear-weapons-free zone.
June 8 - China conducts a nuclear test at the Lop Nur test site.
September 11 - United Nations approves the Comprehensive Test Ban Treaty (CTBT).
November 26 -The last of the nuclear warheads stationed in Belarus were finally removed to Russia.
March - At least 35 workers are contaminated with minor radiation after a fire and explosion occurred at a reprocessing plant at Tokaimura, Japan.
July 2 - U.S. begins a round of sub-critical nuclear related tests at the Nevada Test Site.
December 22 - U.S. implodes the last Minuteman II missile silo.
February 24 - France's National Assembly votes unanimously to ratify the CTBT.
May 11 - India conducts three underground nuclear tests, its first in 24 years. One of the tests is a thermonuclear weapon.
May 13 - India conducts two more nuclear tests.
May 28 - Pakistan conducts five nuclear tests in response to India's nuclear tests.
May 30 - Pakistan conducts its sixth nuclear weapons test. The explosion is in the 1 to 5 kiloton range.
July 23 - President Bill Clinton signs the National Missile Defense act and says threat, cost, technological status of national missile defense and adherence to a renegotiated ABM treaty are the four criteria in making his decision to deploy such a system.
September 30 - An accident at the uranium processing plant at Tokaimura, Japan exposes fifty-five workers to radiation.
October 13 - U.S. Senate fails to ratify the Comprehensive Test Ban Treaty.
October 15 - First of 150 Minuteman III Missile silos destroyed.