No other weapon has the incredible destructive capacity of a nuclear bomb. First developed in the United States by the Manhattan Project in 1945, nuclear weapons harness the power of the atom to unleash enormous amounts of energy capable of utter devastation. In the hands of a rogue state or terrorist group, an atomic bomb could result in a catastrophe of unprecedented scale. In one scenario contemplated by the RAND Corporation, an attack at the Port of Long Beach in California could kill 60,000 people instantaneously, expose 150,000 to hazardous radiation, force some two to three million people to relocate from the contaminated area, and cause ten times the economic damage of the September 11 attacks. According to the report, "the blast and subsequent fires might destroy the infrastructure and all ships in the Port of Long Beach and adjoining Port of Los Angeles, which combined comprise the nation's busiest port of entry and handle about one-third of the nation's imports." The effects of such an attack would be felt worldwide.
Nuclear Weapon Design
Nuclear weapons come in two basic types determined by
the type of reaction used to produce the bomb's energy. A traditional
nuclear bomb, like those used during World War II against Japan, derives
its energy from the process of fission, in which the energy used to
hold an atom's nucleus together is released when the nucleus fragments.
The material used to create a fission bomb can be composed of
Plutonium-239 or uranium enriched to weapons-grade levels (approximately
90 percent of the isotope Uranium-235). When a sufficiently large
amount (called a "critical mass") of either isotope is accumulated, the
material can self-sustain a chain reaction of fission after the first
fission incident (when a stray neutron collides with a nucleus of 239Pu
or 235U). In order to prevent a premature explosion, nuclear
material must be kept in a sub-critical state prior to detonation, when
the mass becomes critical and explodes. Two methods have been used to
bring sub-critical masses of nuclear material to critical mass. The
first is the gun-type, in which a bullet of uranium is propelled down a
cylinder by a conventional explosion until it collides with a larger,
but still sub-critical, amount of uranium, causing the total mass to
become supercritical and explode. The other type, while significantly
more difficult to build, is the more efficient implosion type, in which a
sub-critical sphere of normal density is compressed by surrounding
conventional explosions into a highly dense, supercritical sphere. The
gun-type bomb works only with uranium (as plutonium has certain
characteristics that causes the fission chain reaction to start prior to
detonation), while the implosion type will work with both materials.
for the BBC's interactive guide to the nuclear fuel cycle and nuclear
A second type of nuclear weapon is the thermonuclear bomb, which uses the energy created by the fusion of two hydrogen nuclei to create explosive yields that dwarf those of standard fission bombs. A standard thermonuclear bomb consists of a fission "primary" and supplies of hydrogen isotopes known as deuterium (which has one extra neutron) and tritium (which has two extra neutrons). The energy produced by the fission primary causes deuterium nuclei to fuse with a tritium nuclei, resulting in a helium nucleus, a neutron, and a tremendous amount of energy.
The Nuclear Nonproliferation Regime
State ownership of these powerful weapons is governed
by the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) [See Annex A
for the full text of the treaty]. The NPT was opened for signature on
June 12, 1968, and it entered into force on March 5, 1970. Today, 189
states are parties-more have joined this treaty than any other arms
limitation or disarmament agreement. The
treaty allows the five states that had developed nuclear weapons prior
to 1968 (the US, the USSR (and subsequently Russia), the United Kingdom,
France, and China) to retain their nuclear weapons while forbidding any
other state party from developing them. To balance this discriminatory
provision, the nuclear weapons states had to promise in Article VI "to
pursue negotiations in good faith on effective measures relating to
cessation of the nuclear arms race at an early date and to nuclear
disarmament, and on a treaty on general and complete disarmament under
strict and effective international control." As a
further hedge against total nuclear dominance by the existing nuclear
weapons states, the treaty both condones and encourages international
cooperation on the peaceful uses of nuclear technology. Article IV of
the NPT describes every country's "inalienable right" to use peaceful
nuclear technology and calls for "the fullest possible exchange of
equipment, materials and scientific and technological information."
India, Pakistan, and Israel  have
not signed the treaty, but have developed nuclear weapons since its
entry into force. North Korea controversially withdrew from the treaty
in order to further its nuclear weapons program.
Withdrawal from the treaty is allowed under Article X, which says that a
government may withdraw if "extraordinary events, related to the
subject matter of this Treaty, have jeopardized the supreme interests of
its country." North
Korea has since tested a nuclear device in October 2006, and some
reports put its arsenal at around eight bombs.
Of the nuclear states-both within the NPT and outside of it-the US and Russia, due to their massive legacy arsenals from the Cold War, have clear nuclear superiority. During the Cold War, the United States and the Soviet Union produced over a thousand metric tons of weapons-grade nuclear material, enough to build approximately 175,000 nuclear warheads. In 1986, at the height of the US and Russian nuclear weapons build up, the two countries possessed over 69,000 nuclear warheads.
Remaining Proliferation Challenges
With the Soviet Union's collapse, new and unexpected
challenges to global security emerged. The fragmentation of the Soviet
Union into more than a dozen fledgling states left nuclear weapons and
materials under precarious security conditions sprawled across territory
spanning eleven time zones. Thousands of warheads on so-called
"launch-on-warning" status were scattered throughout Russia, Belarus,
Kazakhstan, and Ukraine. Well-documented instances of disruption of
their command and control raised serious questions over the possibility
of accidental launches. As centralized Soviet authority crumbled, so did
the rigorous security practices governing its fissile materials and
nuclear weapons. Russia's weakened economy and its poorly secured
nuclear infrastructure placed its weapons complex at risk of becoming a
"Wal-mart" for terrorists and rogue states.
The United States Congress first took action to secure the Soviet nuclear infrastructure in 1991, passing the Soviet Nuclear Threat Reduction Act(Public Law 102-228). Commonly referred to as the "Nunn-Lugar" program after the two senators who pioneered its creation-Senator Sam Nunn (D-GA) and Senator Richard Lugar (R-IN)-the legislation gave the president the authority to establish a collaborative program to help the former Soviet Union protect and dismantle its stockpiles of nuclear weapons, technologies, and delivery systems. Run by the Department of Defense, Cooperative Threat Reduction (CTR) grew to have its own budget line and blossomed into a $400 million per year suite of programs. While dismantling nuclear warheads and nuclear weapons infrastructure is only part of the CTR program, it remains the most highly visible among Congress members and the American public alike. While CTR programs remain solely under the jurisdiction of the Defense Department, cooperative nonproliferation (CNP) programs that draw from the CTR toolkit now reside in several other Executive Departments (Energy and State being most prominent) and take many different paths to ensure that nuclear weapons, the materials to make them, and the know-how to put them together remain out of terrorist and rogue government hands.
CTR activities have seen many successes in reducing the "loose nukes" threat posed by Russia's nuclear arsenal. The Department of Defense releases a "CTR Scorecard" approximately every three months to document its work. The latest release, current as of 5 April 2007, shows that almost 7,000 nuclear weapons have been dismantled under the CTR program.
- According to the Federation of American Scientists, building a nuclear weapon, with all the materials on hand, is frighteningly easy. "Although talented people are essential to the success of any nuclear weapons program, the fundamental physics, chemistry, and engineering involved are widely understood; no basic research is required to construct a nuclear weapon."
- The clause in Article IV of the NPT that maintains the right of all states to pursue the nuclear fuel cycle for peaceful purposes says nothing about "break-out potential." Any program that can enrich uranium to produce nuclear fuel is capable of enriching uranium for nuclear weapons. According to International Atomic Energy Agency (IAEA) Director General Mohammad ElBaradei, the world could see twenty to thirty "virtual nuclear weapons states, meaning countries that could move within months into converting their civilian capacity or capability into a weapons program."
- States have been able to circumvent the measures in place for verification of the NPT by the IAEA, which has raised questions over the effectiveness of the entire regime. North Korea's withdrawal from the regime and subsequent weapons development points to the need for "compliance management" strategies, including creating a pathway through which states can return to compliance. The seeming inability of the regime to deal effectively with Iran's nuclear ambitions continues to be a further sign of weakness.
Q: How many nuclear
weapons does the US have? What about other countries?
A: The precise number of nuclear weapons controlled by states is classified, so most numbers are only rough estimates (some of which are very rough). Below is a table from the Federation of American Scientists that includes the most recent weapon stockpile estimates for confirmed nuclear states as of 2 May 2007:
Nuclear Warheads (appx.)
|a These estimates include only deployed warheads. The total stockpiles for France and the UK are unknown.|
|b No publicly available evidence exists that North Korea has operational warheads.|
Q: How is the yield of a nuclear weapon measured?
A: A nuclear weapon's yield is its explosive force. Yields are most often measured in kilotons (kt) or megatons (Mt). One kiloton of explosive force is equal to that produced by 1,000 tons (2 million pounds) of TNT. One megaton of explosive force is equal to that produced by 1,000,000 tons (2 billion pounds) of TNT. The largest bomb ever detonated by the US was exploded in a test codenamed "Bravo;" the bomb yielded 15 megatons of force. The largest nuclear explosion of all time was orchestrated by the Soviet Union in 1961. The "Tsar Bomba" (King of all Bombs) had a yield of 57 megatons.
Q: What is a boosted fission weapon?
A: In a traditional fission weapon, not all of the nuclear material undergoes fission, reducing the bomb's actual yield compared to its potential yield. A boosted weapon is a fission weapon with small amounts of deuterium and tritium gas placed at the weapon's core. The fission explosion causes hydrogen isotopes in the deuterium and tritium to undergo fusion (as in a thermonuclear weapon), which results in "an intense burst of high-energy neutrons (along with a small amount of fusion energy as well) that fissions the surrounding material more completely. This approach, called boosting, is used in most modem nuclear weapons to maintain their yields while greatly decreasing their overall size and weight."
Q: What measures has the US taken to address unsecured nuclear weapons and materials in the FSU?
A: While the US has several programs to address nuclear weapons and materials security in the former Soviet Union, the Materials Protection, Control, and Accounting (MPC&A) programs have arguably been the most successful. MPC&A seeks to 1) increase physical security at nuclear weapons and materials facilities, 2) control access to and movement of nuclear materials, and 3) provide accurate accounting information on nuclear weapons and materials. [See MPC&A Issue Brief]
Q: Who verifies compliance with the NPT?
A: The International Atomic Energy Agency is charged with verification of each states party's NPT adherence. States Party to the NPT are required by Article III to conclude safeguards agreements with the IAEA to ensure that they are following through with their obligations. However, 31 of the 189 States Party have yet to conclude the NPT comprehensive safeguards agreement.
- The largest nuclear bomb ever detonated by the US had a yield of 15 megatons. The largest nuclear explosion of all time was the 57 megaton "Tsar Bomba" (King of all Bombs) tested by the Soviet Union on 30 October 1961 in an archipelago in the Arctic Sea.
- Almost 7,000 nuclear warheads have been dismantled under the Cooperative Threat Reduction program.
- Four kilograms of plutonium, which is about the size of a baseball, could be turned into a bomb about as powerful as the one that destroyed Hiroshima.
- Documents found in November 2001 in a Kabul building believed to be an al Qaeda safe house contained details about how to produce nuclear weapons.
- At its peak, the Soviet nuclear weapons complex had over 40,000 nuclear warheads. Russia now has approximately 15,000 warheads, many of which remain vulnerable to terrorist seizure.
- Depending on environmental factors, such as building materials and weather conditions, the heat from a nuclear bomb can create a "firestorm" of flames and air heated to over 1850°F (~1000°C), hot enough to melt glass and many metals. In a Hiroshima-sized explosion, this firestorm could incinerate everything within about 1.2 miles (1.9 km) from ground zero. [For customizable scenarios for a few cities, including Washington, DC, see the FAS Nuclear Weapon Effects Calculator]
- The Nunn-Lugar Cooperative Threat Reduction Act of 2007 (S.198, under consideration), seeks to improve the CTR programs by reducing funding restrictions which had been imposed by prior Congressional action.
National Defense Authorization Act for Fiscal Year 2008 (H.R.1585, as
reported, under consideration) called for the following funding amounts
for the Cooperative Threat Reduction Program:
- For strategic offensive arms elimination in Russia, $77,900,000;
- For nuclear weapons storage security in Russia, $23,000,000;
- For nuclear weapons transportation security in Russia, $37,700,000;
- The Ensuring Implementation of the 9/11 Commission Report Act (S. 328, under consideration), calls for, inter alia, the establishment of an Office of Nonproliferation Programs within the Executive Office of the President, the removal of restrictions on Cooperative Nonproliferation programs, and funding for a thorough accounting of Russia's nuclear weapons.
Applicable Treaties, Legislation, and Other International Agreements
- The Treaty on the Non-Proliferation of Nuclear Weapons (signed in 1960 and entering into force in 1970) underwrites the basic tenets of the international community's nonproliferation regime. [See Annex A]
- Title II of the Conventional Forces in Europe Treaty Implementation Act of 1991 (Public Law 102-228), known as the Soviet Nuclear Threat Reduction Act of 1991, authorized what has come to be known as the Cooperative Threat Reduction program.
- The Strategic Arms Reduction Treaty (START I), signed on 31 July 1991, places strict limits on the number and type of offensive arms that the US and Russia (as the successor of the Soviet Union) can have. START I also mandates detailed notification of any changes and complex verification inspections.
- The Treaty Between The United States Of America And The Union Of Soviet Socialist Republics On The Reduction And Limitation Of Strategic Offensive Arms (START II), signed January 3, 1993, lowered the limits of weapons permissible from START I. The treaty deals more with missiles and other delivery systems than with the warheads they carry.
- The Comprehensive Nuclear Test-Ban Treaty (CTBT), which was opened for signature on 24 September 1996, orders all parties "not to carry out any nuclear weapon test explosion or any other nuclear explosion, and to prohibit and prevent any such nuclear explosion at any place under its jurisdiction or control." This prohibition does not apply to the use of nuclear weapons in combat. While the US has signed the CTBT, the treaty was never ratified by the Senate. The treaty cannot enter into force globally until all forty-four states listed in Annex II have ratified the treaty. Annex II states that have yet to ratify are China, Colombia, Egypt, India, Indonesia, Iran, Israel, North Korea, Pakistan, and the United States.
- The Strategic Offensive Reductions Treaty (known as both SORT and the Treaty of Moscow) was signed on 24 May 2002 by US President George W. Bush and Russian Federation President Vladimir Putin. The Treaty, which relies on the verification and notification methods used in START I, obligates the US and Russia to reduce their deployed, strategic nuclear stockpiles to 1,700 to 2,200 warheads by December 31, 2012.
- A proposed Fissile Material Cut-off Treaty (FMCT) would ban the production of fissile material for use in weapons, though it excludes HEU or plutonium not used for non-weapons activities and non-fissile weapons material like tritium. Additionally the agreement would not take any action on existing stockpiles. The US submitted a draft FMCT to the Conference on Disarmament which did not include verification provisions; current official US policy is that an FMCT cannot achieve "effective verification."
- The threat of "loose nukes" in the former Soviet Union is still prevalent, but the budget for the Department of Defense's Cooperative Threat Reduction program is declining, as is political interest in threat reduction and nonproliferation. New cooperative strategies that sustain and further develop CNPs existing investments are urgently needed.
National Security Council designee should spearhead an interagency
process to reassess the global role of cooperative nonproliferation
efforts in today's context. One of the main objectives of this
reassessment is to produce a detailed and timely analysis, including an
"exit strategy" for US assistance where appropriate. This strategy
should include provisions on how to sustain security upgrades to Russian
nuclear warheads and materials once US assistance ends, which will help
move the US-Russian relationship away from patronage and toward
partnership. Roles for the G8 Global Partnership and the Global
Initiative to Combat Nuclear Terrorism should also be explored.
[See Book Recommendations #1, #3 and #5]
global reassessment (mentioned above) should be used as the foundation
for an ongoing process within the US government to set priorities,
ensure coherence, and streamline ongoing activities. Given the threat of
nuclear weapons, this process should push for the acceleration of
dismantlement and security efforts. After fifteen years, CTR still has
approximately 6,330 warheads to deactivate and 830 nuclear-capable
Intercontinental Ballistic Missiles (ICBMs) to destroy.
[See Book Recommendation #2]
the start of any program, the US agency involved should build consensus
with the respective host country regarding the threats and ensure host
country support for the objectives and commitments to sustain the
efforts after US support ends. Russia and the US have experienced
numerous conflicts over the nature of the threat (improvised nuclear
devices versus radiological dispersal devices) and US access to
sensitive nuclear sites.
[See Book Recommendation #6]
a bicameral congressional task force whose objective is to regularly
provide briefings from a broad array of the actors involved in actual
implementation of CNP initiatives. This can help expedite the process of
securing Russia's nuclear weapons. The Defense Threat Reduction
Agency's Public Affairs office should be encouraged to actively promote
[See Book Recommendations #7 and #15]
scientist redirect programs to meet the needs of other government
programs. US programs to secure nuclear weapons and material create a
demand in Russia for security technology. Former nuclear weapons
scientists can help design this technology and create new safeguard
equipment to aid CNP programs. By coordinating programs to redirect
scientists with internal US Government programs to achieve specific
technological advances needed to solve our own energy, nonproliferation,
counterterrorism, intelligence and other needs, the US could better
achieve its existing nonproliferation goals with respect to brain drain
while exploring potential technological solutions to existing security
concerns at lower cost.
[See Book Recommendations #8 and #17]
Pentagon, as the lead department in warhead dismantlement efforts,
should team with the State Department to create a "Master Plan" for
countries involved in CTR efforts. This will ensure that other foreign
policy objectives (such as human rights and democracy promotion) do not
interfere with the US's interest in dismantling and securing Russian
[See Book Recommendation #10]
funding "ceilings" on specific CTR projects, as well as the CTR
certification requirements, should be eliminated. If Russia provides the
US with an opportunity to dismantle more warheads or secure more
nuclear material, the CTR program should have the flexibility to take
advantage of the situation.
[See Book Recommendations #14 and #21]
The Treaty on the Non-Proliferation of Nuclear Weapons (NPT)
Each nuclear-weapon State Party to the Treaty undertakes not to transfer to any recipient whatsoever nuclear weapons or other nuclear explosive devices or control over such weapons or explosive devices directly, or indirectly; and not in any way to assist, encourage, or induce any non-nuclear weapon State to manufacture or otherwise acquire nuclear weapons or other nuclear explosive devices, or control over such weapons or explosive devices.
Each non-nuclear-weapon State Party to the Treaty undertakes not to receive the transfer from any transferor whatsoever of nuclear weapons or other nuclear explosive devices or of control over such weapons or explosive devices directly, or indirectly; not to manufacture or otherwise acquire nuclear weapons or other nuclear explosive devices; and not to seek or receive any assistance in the manufacture of nuclear weapons or other nuclear explosive devices.
1. Each non-nuclear-weapon State Party to the Treaty
undertakes to accept safeguards, as set forth in an agreement to be
negotiated and concluded with the International Atomic Energy Agency in
accordance with the Statute of the International Atomic Energy Agency
and the Agency's safeguards system, for the exclusive purpose of
verification of the fulfillment of its obligations assumed under this
Treaty with a view to preventing diversion of nuclear energy from
peaceful uses to nuclear weapons or other nuclear explosive devices.
Procedures for the safeguards required by this article shall be followed
with respect to source or special fissionable material whether it is
being produced, processed or used in any principal nuclear facility or
is outside any such facility. The safeguards required by this article
shall be applied to all source or special fissionable material in all
peaceful nuclear activities within the territory of such State, under
its jurisdiction, or carried out under its control anywhere.
2. Each State Party to the Treaty undertakes not to provide: (a) source or special fissionable material, or (b) equipment or material especially designed or prepared for the processing, use or production of special fissionable material, to any non-nuclear-weapon State for peaceful purposes, unless the source or special fissionable material shall be subject to the safeguards required by this article.
3. The safeguards required by this article shall be implemented in a manner designed to comply with article IV of this Treaty, and to avoid hampering the economic or technological development of the Parties or international cooperation in the field of peaceful nuclear activities, including the international exchange of nuclear material and equipment for the processing, use or production of nuclear material for peaceful purposes in accordance with the provisions of this article and the principle of safeguarding set forth in the Preamble of the Treaty.
4. Non-nuclear-weapon States Party to the Treaty shall conclude agreements with the International Atomic Energy Agency to meet the requirements of this article either individually or together with other States in accordance with the Statute of the International Atomic Energy Agency. Negotiation of such agreements shall commence within 180 days from the original entry into force of this Treaty. For States depositing their instruments of ratification or accession after the 180-day period, negotiation of such agreements shall commence not later than the date of such deposit. Such agreements shall enter into force not later than eighteen months after the date of initiation of negotiations.
1. Nothing in this Treaty shall be interpreted as
affecting the inalienable right of all the Parties to the Treaty to
develop research, production and use of nuclear energy for peaceful
purposes without discrimination and in conformity with articles I and II
of this Treaty.
2. All the Parties to the Treaty undertake to facilitate, and have the right to participate in, the fullest possible exchange of equipment, materials and scientific and technological information for the peaceful uses of nuclear energy. Parties to the Treaty in a position to do so shall also cooperate in contributing alone or together with other States or international organizations to the further development of the applications of nuclear energy for peaceful purposes, especially in the territories of non-nuclear-weapon States Party to the Treaty, with due consideration for the needs of the developing areas of the world.
Each party to the Treaty undertakes to take appropriate measures to ensure that, in accordance with this Treaty, under appropriate international observation and through appropriate international procedures, potential benefits from any peaceful applications of nuclear explosions will be made available to non-nuclear-weapon States Party to the Treaty on a nondiscriminatory basis and that the charge to such Parties for the explosive devices used will be as low as possible and exclude any charge for research and development. Non-nuclear-weapon States Party to the Treaty shall be able to obtain such benefits, pursuant to a special international agreement or agreements, through an appropriate international body with adequate representation of non-nuclear-weapon States. Negotiations on this subject shall commence as soon as possible after the Treaty enters into force. Non-nuclear-weapon States Party to the Treaty so desiring may also obtain such benefits pursuant to bilateral agreements.
Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a Treaty on general and complete disarmament under strict and effective international control.
Nothing in this Treaty affects the right of any group of States to conclude regional treaties in order to assure the total absence of nuclear weapons in their respective territories.
1. Any Party to the Treaty may propose amendments to
this Treaty. The text of any proposed amendment shall be submitted to
the Depositary Governments which shall circulate it to all Parties to
the Treaty. Thereupon, if requested to do so by one-third or more of the
Parties to the Treaty, the Depositary Governments shall convene a
conference, to which they shall invite all the Parties to the Treaty, to
consider such an amendment.
2. Any amendment to this Treaty must be approved by a majority of the votes of all the Parties to the Treaty, including the votes of all nuclear-weapon States Party to the Treaty and all other Parties which, on the date the amendment is circulated, are members of the Board of Governors of the International Atomic Energy Agency. The amendment shall enter into force for each Party that deposits its instrument of ratification of the amendment upon the deposit of such instruments of ratification by a majority of all the Parties, including the instruments of ratification of all nuclear-weapon States Party to the Treaty and all other Parties which, on the date the amendment is circulated, are members of the Board of Governors of the International Atomic Energy Agency. Thereafter, it shall enter into force for any other Party upon the deposit of its instrument of ratification of the amendment.
3. Five years after the entry into force of this Treaty, a conference of Parties to the Treaty shall be held in Geneva, Switzerland, in order to review the operation of this Treaty with a view to assuring that the purposes of the Preamble and the provisions of the Treaty are being realized. At intervals of five years thereafter, a majority of the Parties to the Treaty may obtain, by submitting a proposal to this effect to the Depositary Governments, the convening of further conferences with the same objective of reviewing the operation of the Treaty.
1. This Treaty shall be open to all States for
signature. Any State which does not sign the Treaty before its entry
into force in accordance with paragraph 3 of this article may accede to
it at any time.
2. This Treaty shall be subject to ratification by signatory States. Instruments of ratification and instruments of accession shall be deposited with the Governments of the United States of America, the United Kingdom of Great Britain and Northern Ireland and the Union of Soviet Socialist Republics, which are hereby designated the Depositary Governments.
3. This Treaty shall enter into force after its ratification by the States, the Governments of which are designated Depositaries of the Treaty, and forty other States signatory to this Treaty and the deposit of their instruments of ratification. For the purposes of this Treaty, a nuclear-weapon State is one which has manufactured and exploded a nuclear weapon or other nuclear explosive device prior to January 1, 1967.
4. For States whose instruments of ratification or accession are deposited subsequent to the entry into force of this Treaty, it shall enter into force on the date of the deposit of their instruments of ratification or accession.
5. The Depositary Governments shall promptly inform all signatory and acceding States of the date of each signature, the date of deposit of each instrument of ratification or of accession, the date of the entry into force of this Treaty, and the date of receipt of any requests for convening a conference or other notices.
6. This Treaty shall be registered by the Depositary Governments pursuant to article 102 of the Charter of the United Nations.
1. Each Party shall in exercising its national
sovereignty have the right to withdraw from the Treaty if it decides
that extraordinary events, related to the subject matter of this Treaty,
have jeopardized the supreme interests of its country. It shall give
notice of such withdrawal to all other Parties to the Treaty and to the
United Nations Security Council three months in advance. Such notice
shall include a statement of the extraordinary events it regards as
having jeopardized its supreme interests.
2. Twenty-five years after the entry into force of the Treaty, a conference shall be convened to decide whether the Treaty shall continue in force indefinitely, or shall be extended for an additional fixed period or periods. This decision shall be taken by a majority of the Parties to the Treaty.
This Treaty, the English, Russian, French, Spanish and Chinese texts of which are equally authentic, shall be deposited in the archives of the Depositary Governments. Duly certified copies of this Treaty shall be transmitted by the Depositary Governments to the Governments of the signatory and acceding States.
 Greg Krikorian, "Effect of Nuclear Blast at Port Would Be National," Los Angeles Times, 16 August 2006, accessed at: http://www.latimes.com/news/local/la-me-nuclear16aug16,1,7213606.story?coll=la-headlines-california.
 Much from the next two paragraphs is taken from the Federation of American Scientists, "Nuclear Weapons Design," Special Weapons Primer, accessed at: http://www.fas.org/nuke/intro/nuke/design.htm. Please visit FAS's website (http://www.fas.org/) for more information.
 Israel has a policy of non-confirmation when it comes to its nuclear weapons status, but is widely believed to have a substantial nuclear weapons capability.
 North Korea joined the IAEA in 1975, but did not ratify the NPT until 1985.
 "Q&A: N Korea nuclear stand-off," BBC News Online, 22 March 2007 accessed at: http://news.bbc.co.uk/2/hi/asia-pacific/2340405.stm.
 Harold Feiveson and Steve Fetter, "Verifying Deep Reductions in Nuclear Forces," in Harold Feiveson, ed., The Nuclear Turning Point: A Blueprint for Deep Cuts and De-alerting of Nuclear Weapons (Washington, DC: The Brookings Institution, 1999): 221.
 Robert S. Norris and Hans M. Kristensen, "NRDC: Nuclear Notebook: Global Nuclear Stockpiles, 1945-2006," Bulletin of the Atomic Scientists, Vol. 62, No. 4 (July/August 2006): 64-66, accessed at: http://www.thebulletin.org/article_nn.php?art_ofn=ja06norris.
 Federation of American Scientists, "Nuclear Weapons Design," op. cit., note 2.
 Mohammad ElBaradei, quoted in Daryl G. Kimball, "Balancing Nuclear 'Rights' and Responsibilities," Arms Control Today Vol. 36, No. 8 (October 2006).
 Guinness World Records, "Most Powerful Nuclear Explosion," (2006), accessed at: http://www.guinnessworldrecords.com/content_pages/record.asp?recordid=53275.
 Federation of American Scientists, "Nuclear Weapons Design," op. cit., note 2.
 International Atomic Energy Agency, "NPT Comprehensive Safeguards Agreement," 16 May 2007, accessed at: http://www.iaea.org/Publications/Factsheets/English/nptstatus_overview.html.
 Federation of American Scientists, "The Comprehensive Nuclear Test-Ban Treaty," accessed at: http://www.fas.org/nuke/control/ctbt/text/ctbt1.htm.
 Federation of American Scientists, "Article I: Basic Obligations," accessed at: http://www.fas.org/nuke/control/ctbt/text/artbyart/art01.htm.
 White House Office of the Press Secretary, "Text of Strategic Offensive Reductions Treaty," (24 May 2002), accessed at: http://www.whitehouse.gov/news/releases/2002/05/20020524-3.html.
 US Mission to the United Nations - Geneva, "USA: White Paper on a Fissile Material Cutoff Treaty - Conference on Disarmament," 18 May 2006, accessed at: http://www.state.gov/t/isn/rls/other/66901.htm.