March 14 - Russia and the Netherlands sign a cooperative agreement for the dismantling of old Russian nuclear warheads and nuclear submarines.
April -The Russian Federation ratifies the Strategic Arms Reduction Treaty (START II).
August 12 - The Russian submarine Kursk sinks in the Barent Sea. All 118 crew members are killed. Several bodies are recovered; the exact cause of the sinking is unknown.
December - The last of the reactors at the Chernobyl nuclear power plant are shut down.
President George W. Bush moves forward in developing a National Missile Defense system. Russia and China oppose its development.
June 29 - Efforts to raise the Russian submarine Kursk begin.
August - Yucca Mountain in Nevada is initially approved to become a storage facility for high-level nuclear waste.
September 11 - Terrorists hijack four commercial aircraft. The Pentagon is damaged by one plane, two planes strike the World Trade Center, destroying both towers, and the fourth plane crashes in rural Pennsylvania.
October - The Kursk is raised and brought to port.
December 13 - The United States announces that it will withdraw from the 1972 Anti-Ballistic Missile treaty.
May 24 - Strategic Offensive Reductions Treaty is signed between the U.S. and Russia. Each nation would be limited to 1,700 to 2,200 strategic nuclear warheads apiece.
October 16 - North Korea tells U.S. officials it has developed a secret nuclear weapons program in violation of the 1994 agreement.
December 21 - The IAEA says North Korea has disabled surveillance devices the agency had placed at the five-megawatt Yongbyon research reactor.
January 10 - North Korea announces it will withdraw from the Nuclear Non-Proliferation Treaty.
February 5 - North Korea announces that it had reactivated its nuclear facilities and is going ahead with their operation "on a normal footing."
February 9 - Iran acknowledges for the first time that it has uranium ore reserves and that it will reprocess the spent fuel. But it insists the nuclear program was designed solely for civilian use.
February 27 - The United States says North Korea has reactivated its five-megawatt nuclear reactor at Yongbyon.
May 12 - North Korea backs out of the only remaining legal obligation blocking its nuclear ambitions, a 1992 pact with South Korea to keep the peninsula free of nuclear weapons.
May 14 - Russia's lower house of parliament votes to ratify the Strategic Offensive Reductions Treaty (Moscow Treaty).
May 29 - Russia's upper house of parliament votes to ratify the Strategic Offensive Reductions Treaty (Moscow Treaty).
July 9 - Ukraine will get $85 million to build a new shield over Chernobyl to stabilize the old "sarcophagus" covering the gaping hole in reactor No. 4.
August 26 - U.N. inspectors have found traces of highly enriched, weapons-grade uranium at an Iranian nuclear facility.
August 26-29 - Six-party talks aimed at ending the standoff over North Korea's suspected nuclear weapons program take place in China.
September 9 - Edward Teller, "father of the H-bomb" dies.
September 25 - The IAEA team in Iran has found additional traces of weapons-grade uranium in Iran.
September 26 - Afghanistan signs, ratifies Comprehensive Nuclear Test Ban Treaty.
October 29 - Iran delivers a report to the IAEA to allay international concern about its nuclear program.
November 10 - The International Atomic Energy Agency reports that Iran has acknowledged producing a small amount of plutonium, a material useable in a nuclear bomb.
December 18 - Iran signs Protocol on Snap UN Nuclear Inspections.
December 19 - Libya has admitted trying to develop weapons of mass destruction. It is discovered that Libya's nuclear weapons program is "much further advanced" than U.S. and British intelligence agencies had thought, and includes centrifuges and a uranium-enrichment program, all necessary components in making a nuclear bomb.
January 10 - U.S. Group to Visit North Korea, tours Yongbyon, the probable location of the plant that is reprocessing spent nuclear fuel rods into plutonium.
January 13 - Libya ratifies the Comprehensive Test Ban Treaty.
January 27 - Pakistani investigators have concluded that at least two of the country's top nuclear scientists -- including Abdul Qadeer Khan, considered the father of Pakistan's nuclear bomb -- provided unauthorized technical assistance to Iran's nuclear weapons program in the late 1980s.
January 31 - Pakistan fires A. Q. Khan, the founder of their nuclear program; he is later pardoned by the Pakistani President.
February 15 - Drawings of a nuclear warhead that Libya surrendered as part of its decision to renounce weapons of mass destruction are discovered to be of 1960s Chinese design, but likely came from Pakistan.
February 20 - The International Atomic Energy Agency has said Libya managed to produce a small amount of plutonium using technology acquired on the black market. The report does not specify the amount.
February 25-28 - Six-party talks aimed at ending the standoff over North Korea's suspected nuclear weapons program take place in China.
March 10 - Libya to allow the IAEA to perform unannounced inspections of atomic facilities.
March 29 - Pakistan rejects a request to allow the International Atomic Energy Agency to inspect its nuclear facilities.
April 2 - International Atomic Energy Agency (IAEA) has found traces of bomb-grade uranium in Iran at sites other than the two already named.
June 22 - India and Pakistan set up a nuclear 'hotline'.
June 23 - Talks resume with North Korea over its suspected nuclear weapons program.
September 2 - South Korea reveals that it had secretly conducted an experiment more than 20 years ago with traces of plutonium.
November 28 - Iran pledges to suspend all activities related to plutonium reprocessing and the enrichment of uranium in a deal with the European Union. Iran's nuclear program has been the focus of much international pressure.
January 1 - India and Pakistan exchange lists of their nuclear facilities. Under the agreement, both countries are to refrain from attacking each other's nuclear facilities in the event of a war.
January 5 - IAEA finds evidence of secret nuclear experiments in Egypt that could be used in weapons programs.
January 5 - International Atomic Energy Agency (IAEA) Director General Mohamed ElBaradei announces that Iran has agreed to grant access to a military site that the U.S. links to a secret nuclear weapons program.
January 22 - North Korea announces it is a nuclear weapons state.
Febuary 4 - The Bahamas sign the Comprehensive Test Ban Treaty (CTBT), bringing the total number of treaty Signatories to 175.
February 23 - Canada declines to participate with the U.S. ballistic missile defense program.
February 24 - President Bush and Russian President Vladimir Putin plan to announce a package of measures today to counter the threat of nuclear terrorism.
February 28 - Iran, Russia sign nuclear fuel agreement that is key to bringing Tehran's first reactor online by mid-2006.
March 6 - Hans Bethe, Nobel Prize winner and former Head of the Theoretical Division during the Manhattan Project dies at the age of 98.
March 10 - Pakistan acknowledges that A.Q. Khan sold Iran high speed centrifuges for uranium separation.
April 4 - U.N. Committee approves Nuclear Terrorism Treaty.
April 13 - United Nations adopts the "International Convention on the Suppression of Acts of Nuclear Terrorism". The goal of the convention is to stop clandestine networks from using or possessing nuclear weapons. It obligates governments to prosecute or extradite individuals who possess radioactive materials or nuclear devices or those who threaten others while possessing such materials.
May 10 - Iranian officials announce their intention to restart work at the Isfahan plant to enrich uranium, ending Iran's suspension of uranium-related projects that was agreed upon in Paris in November 2004.
May 11 - North Korea issues a statement saying 8,000 fuel rods have been extracted from its five-megawatt Yongbyon nuclear reactor after its shutdown on April 18, 2005.
June 9 - The International Atomic Energy Agency (IAEA) announces that Iran's claim regarding the source of uranium contamination on its centrifuges appears correct. After the IAEA detected uranium traces on centrifuges in Iran in 2003, the Iranian government asserted that the contamination stemmed from earlier use in Pakistan.
June 11 - The International Atomic Energy Agency (IAEA) verifies the freeze of uranium enrichment activities at Natanz, Iran. The Iranian government agreed to suspend its enrichment activities while engaged in negotiations with France, Germany, and Great Britain (EU-3).
July 29 - Russia announced the destruction of the final SS-18 Satan missile launcher.
July 31 - Iran resumes nuclear activities.
August 6 - India and Pakistan announce the establishment of an emergency nuclear hotline and notification of future missile tests.
August 16 - Russia stops use of rail-based missiles.
August 24 - Pakistan acknowledges that A.Q. Khan supplied North Korea with centrifuges and their designs.
September 19 - North Korea agrees to give up all nuclear weapons and existing nuclear programs and return to the Non-Proliferation Treaty.
September 23 - The International Atomic Energy Agency (IAEA) reports that there is no indication that nuclear material in Iraq is being diverted for undeclared activities, following a two-day inspection by agency officials.
October 3 - India and Pakistan sign an agreement for advanced notification of ballistic missile tests.
October 7 - The International Atomic Energy Agency (IAEA) and its head Mohamed ElBaradei win the Nobel Peace Prize.
October 7 - The last of more than 62,000 waste shipments departs Rocky Flats, Colorado, signaling the end of a massive ten-year cleanup effort at the former nuclear weapons facility.
November 16 - Iran starts converting new uranium batch.
November 18 - Iran admits having nuclear black market data.
January 2 - Iran rejects a Russian offer to produce nuclear fuel in its plants for Iran, the latest effort to resolve a diplomatic impasse over Tehran's nuclear program.
January 3 - North Korea claims it will not return to talks with the United States unless financial restrictions are lifted on several North Korean companies.
January 9 - Iran says nuclear research has resumed.
January 19 - French President Jacques Chirac announces during his first major speech on France's nuclear weapons strategy since 2001 that his country would be ready to use nuclear weapons against any state that carried out a terrorist attack or used weapons of mass destruction against it.
February 13 - Iran "resumes" nuclear enrichment.
March 2 - India and the United States seal a landmark civilian nuclear cooperation pact.
April 22 - IAEA reports that Iran has enriched uranium.
August 21 - The International Atomic Energy Agency (IAEA) reports that more than one hundred incidents of illegally transported nuclear or radioactive materials occurred in the past year.
September 8 - The five ex-Soviet nations of Tajikistan, Turkmenistan, Kyrgyzstan, Kazakhstan, and Uzbekistan pledge to not produce, buy, or allow the deployment of nuclear weapons on their soil.
October 8 - North Korea tests a nuclear device, its yield was quite low (about 1 kiloton).
October 23 - Mohammed El Baradei, the head of the International Atomic Energy Agency, reveals that Iranian technicians have assembled 164 centrifuges, and they are days away from being able to begin the enrichment process.
November 24 - China and Pakistan agree to a trade deal that includes continued joint development of nuclear technology.
December 18 - President George W. Bush signs legislation allowing for nuclear cooperation between India and the United States.
December 22 - Six party talks that aim at persuading North Korea to give up its nuclear weapons program end without any progress.
February 13 - After a five-year negotiation stalemate, an agreement is reached on North Korea's denuclearization. In exchange for North Korea shutting down its Yongbyon nuclear facility and permitting the International Atomic Energy Agency to conduct inspections, the U.S. will supply the country with energy aid.
April 10 - The United States agrees to unfreeze $25 million dollars in assets going to North Korea in exchange for the shutdown of the Yongbyon nuclear facility.
April 10 - In defiance of two United Nations resolutions, Iran announced that it is now capable of industrial-scale uranium production.
May 11 - Iran Turns Away IAEA inspectors, continuing the ongoing questions about Iran's nuclear program
June 5 - U.S. to Allow START pact to lapse
June 17 - North Korea invites nuclear inspectors from the UN to discuss shutting down its Yongbyon reactor and fuel reprocessing plant.
July 16 - The International Atomic Energy Agency verifies that North Korea's Yongbyon nuclear facility has shut down per an agreement with the United States.
August 29 - Six nuclear-armed missiles without any special guard are loaded onto a B52 bomber and transported from the Minot Air Force Base in North Dakota to the Barksdale Air Force Base in Louisiana.
September 6 - Israel launched an air strike in northeastern Syria. On October 13, American officials confirmed that the site was a partially built nuclear reactor.
November 1 - Paul Tibbets, the pilot of the Enola Gay, the plane responsible for dropping the atomic bomb on Hiroshima in 1945, dies at the age of ninety-two.
November 6 - The Federation of American Scientists (FAS) acquires a document showing that the U.S. has nuclear strike plans for states seeking to attain weapons of mass destruction. The document contains nuclear strike options for countries such as Libya, Syria, Iran, Iraq, and North Korea.
February 20 - U.S. military uses a ship-launched Raytheon Co. Standard Missile-3 missile to destroy a crippled National Reconnaissance Office satellite.
March 22 - President Nicolas Sarkozy dedicated "Le Terrible," the newest addition to France's fourth generation of nuclear-armed submarines, the "Triomphant" class.
May 6 - U.S. and Russia sign bilateral agreement to share nuclear technology and materials.
June 5 - The U.S. completed the transfer of 550 metric tons of "yellowcake" uranium from Iraq to Canada.
June 26 - North Korea makes a declaration of non-weaponized nuclear material, indicating it has 30kg of plutonium.
June 27 - North Korea symbolically blows up the cooling tower at its Yongbyon nuclear reactor.
September 22 - North Korea asks the International Atomic Energy Agency to remove its seals and cameras to resume activity at the Yongbyon nuclear facility.
September 27 - The U.S. House of Representatives approves the U.S.-India nuclear deal, the first time that nuclear trade has been allowed with a country that acquired nuclear weapons outside of the nuclear Non-Proliferation Treaty.
October 1 - The Senate agreed to a deal with India to allow civilian nuclear trade between the two countries/
October 11 - The State Department removed North Korea from its list of state sponsors of terrorism after North Korea agreed to resume dismantling the plutonium plant at Yongbyon and allow some inspections.
October 18 - In response to the U.S.-India nuclear deal, China announces a deal to provide Pakistan with two new nuclear power plants.
October 27 - The International Atomic Energy Agency, announced that there were 250 thefts of radioactive material throughout the world last year.
February 2 - India signs an inspection agreement with the International Atomic Energy Agency(IAEA); thus fulfilling a major precondition for nuclear-exporting countries to begin supplying India with nuclear materials.
February 6 - A Pakistani court orders the release of A.Q. Khan, the "father of the nuclear bomb," who had been held under house arrest for five years.
February 11 - United States, ahead of schedule, meets its commitment under the Moscow Treaty to reduce the number of its deployed strategic nuclear warheads to 2,200.
February 16 - British and French submarines loaded with nuclear weapons collide in the middle of the Atlantic Ocean.
March 20 - A nuclear-powered U.S. submarine collides with a U.S. Navy ship in the Strait of Hormuz near Iran.
March 23 - Five central Asian nations sign the Treaty on a Nuclear-Weapon-Free Zone in Central Asia: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan.
April 27 - North Korea announces that it has re-started the production of weapons-grade plutonium through the reprocessing of spent nuclear reactor fuel rods.
May 25 - North Korea conducts its second nuclear test. The blast of about one-third the power of the bomb dropped on Hiroshima.
July 6 - United States President Barack Obama and Russian President Dmitri Medvedev reached a preliminary agreement on reducing their countries' strategic nuclear weapons stockpiles. The agreement commits both sides to modest decreases as they draft a new arms control treaty to replace START, which expires on December 5, 2009.
July 28 - India becomes the sixth country in the world to build its own nuclear-powered submarine after the United States, Russia, France, the UK, and China.
September 18 - President Barack Obama scraps the Bush administration's plans for a missile defense system in Eastern Europe. The plans called for a radar system in the Czech Republic and ground-based interceptor missiles in Poland.
September 30 - Iran announces the existence of its second uranium enrichment facility, this one in an underground bunker near the holy city of Qom.
October 9 - The 2009 Nobel Peace Prize was awarded to President Barack Obama primarily for his "vision of and work for a world without nuclear weapons."
December 5 - U.S. and Russian officials allowed the Strategic Arms Reduction Treaty (START) to lapse.