Nuclear Weapons Proliferation

I -INTRODUCTION
Nuclear Weapons Proliferation, the spread of nuclear weapons to countries or terrorist organizations that formerly did not possess them. Many observers believe that the problem of nuclear weapons proliferation is likely to be one of the most important issues facing the United States and the world for many years to come. The 1968 Treaty on the Non-Proliferation of Nuclear Weapons (NPT) attempted to address the problem, but the number of countries possessing nuclear weapons has grown since the treaty went into effect.

II -WHO POSSESSES NUCLEAR WEAPONS?
Nuclear weapons were first developed by the United States during World War II (1939-1945) as a result of a massive, secret program known as the Manhattan Project. The United States tested the first nuclear weapon in July 1945 at Alamogordo in the New Mexico desert, and then used two nuclear weapons against the Japanese cities of Hiroshima (August 6, 1945) and Nagasaki (August 9, 1945). These are the only times nuclear explosives have been used as a weapon, although there have been more than 2,000 nuclear weapon tests and more than 100 experiments using nuclear explosives for peaceful purposes, such as excavation.

Today, the United States and seven other countries have openly declared that they possess nuclear weapons and have conducted one or more nuclear test explosions to demonstrate this capability. The countries and the dates of their first nuclear test are: Russia (first test conducted by the former Union of Soviet Socialist Republics, 1949); Britain (1952); France (1960); China (1964); India (peaceful nuclear explosion, 1974; nuclear weapons test, 1998); Pakistan (1998); and North Korea (2006). Israel is generally believed to possess nuclear weapons, although it has not acknowledged this and is not known to have conducted a nuclear test. Including Israel, the total number of countries generally recognized as possessing nuclear weapons is nine.

A tenth country, South Africa, has also admitted that it developed a small arsenal of nuclear weapons (first weapon completed, 1977), but it dismantled this arsenal in the early 1990s. When the Soviet Union broke apart in 1991, 3 of the 15 newly independent countries, in addition to Russia, had nuclear weapons on their territory. By the mid-1990s, the three countries—Belarus, Kazakhstan, and Ukraine—had transferred all of these nuclear weapons to Russia. Virtually all countries of the world—other than the nine nations believed to possess nuclear weapons today—have formally pledged not to manufacture them. This pledge was made under the 1968 Treaty on the Non-Proliferation of Nuclear Weapons (NPT), which entered into force in 1970. The treaty has been ratified by 187 nonnuclear weapon states. Many nations have expressed concern, however, that one such party to the treaty, Iran, may be actively seeking to develop such weapons.

No terrorist organizations possess nuclear weapons. Al-Qaeda is known to desire them, however, and a Japanese cult, the Aum Shinrikyo, began an effort to develop them in the late 1980s, but was unsuccessful.

III -HOW ARE NUCLEAR WEAPONS MADE?
The nuclear weapons that the United States developed through the Manhattan Project are known as “atomic” or “fission” weapons because they obtain their energy from the splitting (or fissioning) of certain highly unstable atoms. Two materials have been used as the core of fission weapons: highly enriched uranium and plutonium. Highly enriched uranium is uranium in which one type of unstable uranium atom, an isotope known as uranium 235 or U-235, has been artificially concentrated. In naturally occurring uranium, U-235 makes up only 0.7 percent of a typical uranium sample, but in fission weapons U-235 is concentrated to much higher levels. Concentrations of more than 90 percent U-235 are considered best for fission weapons, but lower concentrations can also be used. The IAEA and virtually all countries, including the United States, treat uranium enriched to more than 20 percent U-235 as potentially usable for weapons. Material enriched above this level is known as “highly enriched uranium” and is protected by special security measures. The process of increasing the concentration of U-235 is performed in a facility known as a uranium enrichment plant.

Irradiating uranium fuel in a nuclear reactor produces plutonium. During the reactor’s operation some uranium atoms absorb an atomic particle known as a neutron, ultimately creating a new element, plutonium. Roughly 1 percent of uranium atoms are transformed into plutonium by this means. The irradiated uranium material is then removed from the reactor in the form of “spent fuel” rods, and chemical processes extract the plutonium from them in a facility known as a reprocessing plant.

To cause a nuclear explosion, the highly enriched uranium or plutonium must be compressed by means of conventional high explosives. The compression causes the nuclear materials to become more dense so as to achieve a supercritical mass that leads to an uncontrolled chain reaction. A nuclear explosion is an uncontrolled chain reaction, whereas the energy generated by a nuclear power plant is a controlled chain reaction. Highly enriched uranium can be detonated by means of a relatively simple, “gun-type” device, in which one quantity of highly enriched uranium is fired into another within a gun-barrel-like cylinder, thereby achieving the necessary supercritical mass. Plutonium must be compressed much more rapidly than highly enriched uranium, however, because plutonium spontaneously emits neutrons that can interfere with the chain reaction that produces the explosion. To detonate plutonium, a much more complicated implosion-type design is required, in which a hollow plutonium sphere is crushed inward with great precision by a series of shaped, high-explosive charges, known as lenses, that surround the plutonium and are detonated at exactly the same moment.

During the Manhattan Project, the United States simultaneously pursued several means for enriching uranium and also produced plutonium. The Manhattan Project scientists had such confidence in the gun-type design that the highly enriched uranium bomb was not tested before it was used against Hiroshima. The scientists were less sure about the more complex implosion design for the Nagasaki bomb, however, and this was the design tested at Alamogordo. Today, nuclear weapons inspectors with the IAEA assume that 25 kg (55 lb) of highly enriched uranium or 8 kg (18 lb) of plutonium would be sufficient to manufacture a nuclear weapon. However, depending on the design of the weapon, considerably less could be used. According to some estimates, it is theoretically possible to develop a nuclear weapon with less than 8 kg of plutonium.

In the late 1940s the United States began to develop a far more potent type of nuclear armament, known as thermonuclear weapons, or the “hydrogen bomb.” These bombs use small fission weapons to create extreme conditions that cause certain types of hydrogen atoms (deuterium and tritium) to fuse together, releasing vast quantities of explosive energy. Some thermonuclear weapons release the equivalent of millions of tons of TNT.
Only five of the states possessing nuclear weapons are known to have developed thermonuclear arms: the United States (first test 1952), Russia (1953), Britain (1957), China (1967), and France (1968). Developing these weapons requires extensive nuclear test detonations. The other, more recent nuclear states have conducted very few (and in some cases no) nuclear tests to avoid calling attention to their nuclear weapon programs, which are often the subject of international criticism. This has slowed their development of thermonuclear weapons.

IV -HOW EASY IS IT TO MAKE THE BOMB?
The most difficult challenge for a country that seeks to build nuclear weapons is obtaining the necessary highly enriched uranium or plutonium. In addition to access to uranium supplies, this requires considerable industrial and scientific capabilities. Even less developed countries, however, such as China, India, North Korea, and Pakistan, have succeeded by concentrating their resources on this effort and, in most cases, by obtaining help from governments or individuals in more advanced countries. For example, China’s nuclear weapon program benefited from early assistance provided by the Soviet Union. India’s program took advantage of Canadian and U.S. assistance provided for peaceful nuclear research, and Pakistan’s program relied on assistance from China, along with technology and equipment secretly obtained from Western European supplier companies. Without such assistance, nuclear weapon programs in these states would have been greatly delayed and might not have succeeded.

A -Enriched Uranium Bombs
Uranium can be enriched using several techniques. The United States nuclear weapons program has relied on the gaseous diffusion method, invented during the Manhattan Project, in which uranium is transformed into a gas (uranium hexafluoride) and pumped through membranes that permit U-235 atoms to pass through slightly more often than other uranium atoms. By repeating this process through many cycles, concentrations of U-235 can be increased to the level needed for nuclear weapons. Britain, France, and China also have relied exclusively on the gaseous diffusion method to produce highly enriched uranium for nuclear weapons. The Soviet Union did so for many years before shifting to the gas centrifuge method.

The gaseous diffusion method uses great quantities of energy. Indeed, during the Manhattan Project, the United States built a hydroelectric dam, under the Tennessee Valley Authority, solely to power the gaseous diffusion enrichment facility at Oak Ridge, Tennessee. A country seeking to develop nuclear weapons secretly would find it difficult to do so using this method today because the energy requirements would be nearly impossible to hide.
Uranium enrichment using high-speed gas centrifuges is far more efficient than gaseous diffusion. In the gas centrifuge process, uranium is also first converted to gaseous uranium hexafluoride. It is then introduced into the centrifuges—rapidly spinning vertical cylinders—where it is swirled at great speed. Under the centrifugal forces created, the bulk of uranium atoms, which are heavier than U-235 atoms, move toward the outside of the centrifuge, allowing product slightly concentrated in U-235 to remain at the center and be drawn off. By linking the gas centrifuges together in what is known as a cascade, this process is then repeated until weapons-usable material is created. Pakistan relies on this method of enrichment for producing highly enriched uranium for nuclear weapons. It is also used in India and, possibly, North Korea. Iran has also built a centrifuge uranium enrichment facility, which it states is intended for its peaceful nuclear energy program.

Other enrichment techniques are the jet nozzle process, used by South Africa, and the electromagnetic isotope separation process, which Iraq used in its unsuccessful effort to enrich uranium before the 1991 Persian Gulf War.
Lasers can also be used to enrich uranium, although to date no country is known to have employed this method for the development of nuclear weapons. In this method, known as laser isotope separation, uranium is transformed into a metal, vaporized, and then targeted with specialized lasers that “excite” U-235 atoms differently from other uranium atoms, permitting a concentrated product to be collected. The process is considered very difficult technically, but it can be conducted in small-scale facilities that can evade detection by the IAEA or foreign intelligence agencies. In 2004 South Korea acknowledged that in 2000 it had conducted secret laser enrichment experiments, creating a tiny amount of very highly enriched uranium. Because it is very hard to detect and can be extremely efficient, the laser enrichment method could pose a significant proliferation risk in the future.

B -Plutonium Bombs
The technology to produce plutonium is technically simpler than that needed to enrich uranium. Nonetheless, plutonium production requires the construction of a series of expensive and relatively complex facilities, including a nuclear research, nuclear power, or plutonium-production reactor; a plant for the manufacture of uranium fuel or targets; and a reprocessing plant. The United States, the Soviet Union (now Russia), Britain, France, and China all produced plutonium for their nuclear weapons programs, in addition to highly enriched uranium. Plutonium is the principal nuclear weapon material used in the Indian, North Korean, and presumed Israeli nuclear weapon programs. Pakistan is also believed to produce plutonium for nuclear weapons.

Because reactors and reprocessing plants, as well as large-scale enrichment plants, are difficult to hide, they may be discovered by other countries, which may attempt to halt their completion by diplomatic pressure or by military attack. In 1981 Israel launched a surprise air strike that destroyed an Iraqi reactor, which Israel feared would be used for plutonium production.
Nonmilitary programs for producing electricity using nuclear power reactors may also employ uranium enrichment and reprocessing. Most nuclear power reactors use uranium fuel that has been enriched to 3 to 5 percent, for example. Today, this material is produced in commercial uranium enrichment plants in Britain, China, France, Germany, Japan, Netherlands, Russia, and the United States. In 2006 Iran declared that its gas centrifuges had enriched uranium to about 3.5 percent. Gas centrifuge enrichment facilities that produce low-enriched uranium for fuel can be reconfigured to produce highly enriched uranium for weapons.

In addition, a number of countries are currently reusing, or plan to reuse, plutonium produced in nuclear power plant fuel. This requires separating the plutonium from the spent nuclear power plant fuel in a reprocessing facility and then mixing the plutonium with unenriched uranium to form new fuel, which is then used in a reactor instead of low-enriched uranium. Britain, France, India, Japan, and Russia are separating plutonium from spent nuclear power plant fuel.

C -Nuclear Bomb Design
Countries seeking to produce nuclear weapons must also develop a reliable design for the weapon. With computer simulations and extensive testing of the nonnuclear components, it is possible for a country to develop a reliable design for a fission weapon without the need for a full-scale nuclear detonation. Some countries also benefit from nuclear weapon design assistance provided by other nations. For example, Pakistan is believed to have received a nuclear weapon design from China in the early 1980s. A senior Pakistani official is known to have provided a copy of this design to Libya and, possibly, Iran and North Korea. A country may wish to forgo a full-scale nuclear test because a test would be clear proof that it was developing nuclear weapons, which, in turn, could lead to international criticism and diplomatic isolation. Israel has adopted this strategy of nuclear ambiguity, as did Pakistan from the late 1980s, when it is believed to have produced its first nuclear weapons, until 1998, when it conducted its first nuclear tests.

V -WHY PREVENTS THE SPREAD OF NUCLEAR WEAPONS?
Nuclear war would have devastating consequences. Even a conflict that involved only the use of one or two fission weapons could cause many hundreds of thousands of deaths and destroy the centers of major cities. Large-scale nuclear war, involving the use of hundreds of thermonuclear weapons, could cause many millions of casualties, destroy nations, and permanently affect the global environment. Although some scholars argue otherwise, virtually all governments believe that the spread of nuclear weapons to additional states will increase the likelihood of nuclear war.
Many of the nations that possess nuclear weapons or have sought to develop them have long had regional conflicts with each other. For example, India and Pakistan have had a serious border dispute over Kashmīr, China and India had a brief border conflict, Israel has fought several wars with neighboring nations in the Middle East, and Iran and Iraq fought an eight-year-long war. North and South Korea, now separated by a demilitarized zone, fought against each other in the Korean War (1950-1953). These regional conflicts and other potential conflicts provide the fundamental reason for the international community to seek to halt the spread of nuclear weapons.

The spread of nuclear weapons can also permit aggressor nations to intimidate neighbors and dominate their regions. Iraq under Saddam Hussein, its former president, is believed to have sought nuclear weapons for this purpose prior to the 1991 Persian Gulf War. In addition, nuclear weapons could be used as a threat by a country seeking to advance a global ideological cause, such as the spread of radical Islamic fundamentalism. A growing new danger is that a national government, or senior officials within that government, might provide nuclear weapons or the materials for making them to terrorist organizations whose views they shared. While nations differ on the particulars of such dangers, they generally agree that their own security is best served by curbing the further spread of nuclear arms.
Nuclear proliferation also inevitably increases the risk of accidents involving nuclear weapons—for example, during transport—which could cause great devastation. This risk may be greatest in less technologically advanced countries whose weapons may not include the built-in safety features found in the nuclear weapons of the more advanced nuclear powers. In some countries, nuclear weapon programs can divert scarce financial and technical resources from urgently needed development projects, a challenge that can be severely worsened for states engaged in open-ended nuclear arms races with rivals.

V -HISTORY OF NONPROLIFERATION EFFORTS
In 1946, in an effort to prevent a nuclear arms race with the Soviet Union and avoid the spread of nuclear weapons to other countries, the United States proposed that all materials usable for nuclear weapons be placed under international control. The Soviet Union, which was not yet a nuclear weapons state, rejected the proposal, known as the Baruch Plan. Fearing that growing interest in nuclear energy would lead nuclear technology to spread uncontrollably, the United States in 1953 launched the Atoms for Peace program. Under the program, the United States offered to share nuclear technology for peaceful purposes with friendly states. U.S. inspections would ensure that transferred items were not diverted for nuclear weapon programs. A new organization, the International Atomic Energy Agency (IAEA), was established in 1957 to take over the inspections. By this time, the Soviet Union had initiated a similar program for its allies, also relying on IAEA inspections.

A -Non-Proliferation Treaty
During the 1960s, as concerns grew that nuclear weapons were continuing to proliferate and as the U.S.-Soviet nuclear arms race accelerated, negotiations began on a global treaty to halt the further spread of nuclear weapons. These negotiations resulted in the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The treaty was opened for ratification in 1968 and entered into force in 1970.The treaty establishes two classes of states: nuclear weapon states and nonnuclear weapon states. Nuclear weapon states are those that had conducted nuclear tests before January 1, 1967—the United States, Soviet Union (now Russia), Britain, France, and China. All other countries are nonnuclear weapon states for the purposes of the treaty.

1 -Terms of the Treaty
Under the treaty, the nuclear weapon states party to the agreement pledge not to transfer nuclear weapons or any other nuclear explosive devices (such as possible peaceful nuclear explosives for large-scale excavations) to any recipient or to “assist, encourage, or induce” any nonnuclear weapon state to manufacture nuclear weapons or any other nuclear explosive devices. The nuclear weapon states are not required by the treaty to give up nuclear weapons.

Nonnuclear weapon states party to the treaty pledge not to manufacture or receive nuclear weapons or any other nuclear explosive devices. To verify that they are complying with these pledges, the nonnuclear weapon states agree to accept IAEA inspections on all of their nuclear activities, an arrangement known as “full-scope safeguards.” All parties to the treaty are prohibited from exporting nuclear equipment or materials to nonnuclear weapon states unless the exported items will be placed under IAEA inspection in the recipient country.

The treaty reaffirms the “inalienable right” of all parties to pursue the peaceful uses of nuclear energy consistent with the prohibition on the development of nuclear explosives and calls on all parties to facilitate the fullest possible sharing of nuclear technology for peaceful purposes.
The treaty states that all parties shall undertake to pursue negotiations in good faith on effective measures relating to cessation of the (U.S.-Soviet) nuclear arms race and to achieve complete and general nuclear disarmament.
Any party may withdraw from the treaty on three months’ notice if it decides that “extraordinary events, related to the subject matter of this Treaty, have jeopardized the supreme interests of its country.”

To persuade the nonnuclear states to agree to the treaty, the nuclear states indicated that they would not use nuclear weapons in an attack on a nonnuclear state unless the state was allied with a nuclear power. However, this pledge was informal and not part of the treaty itself. Since then, Britain and the United States have stated that they might respond with a nuclear attack against a nonnuclear state that used chemical or biological weapons. Some observers believe that preventive war doctrines, such as those articulated by the administration of U.S. President George W. Bush, may have the unintended effect of encouraging some nonnuclear states to develop nuclear weapons for self-protection.

2 -Treaty Limitations
The treaty currently has five nuclear weapon state members and 187 nonnuclear weapon state members. India, Israel, and Pakistan never joined the treaty, thereby reserving the legal right to develop nuclear weapons. North Korea became a party to the treaty in 1985 but renounced it in 2003, exercising its rights under the treaty’s withdrawal provisions. North Korea’s action highlighted one of the treaty’s important limitations.

The treaty’s provision affirming the right of parties to pursue the peaceful uses of nuclear energy can also be exploited by states seeking nuclear weapons. The provision has been interpreted as permitting states to operate nuclear reactors and the facilities needed to fuel them, including enrichment and reprocessing plants, provided they are all placed under IAEA inspection. This arrangement could permit a country to stockpile highly enriched uranium (used in some research reactors) or plutonium while under IAEA supervision and to then withdraw from the treaty on 90 days’ notice. This would leave the country with the materials needed for nuclear weapons. Some countries have expressed concern that Iran, a nonnuclear weapon state party to the NPT, is constructing a uranium enrichment plant with this strategy in mind.

B -Nuclear Suppliers Group
In the early 1970s the NPT Exporters Committee was established to implement the export control provisions of the treaty. In 1974 India conducted a nuclear explosion that it claimed was intended to demonstrate that such explosions could be used for peaceful purposes. India’s test explosion nevertheless underscored the dangers of further proliferation. In 1978 the principal nuclear supplier countries, including states such as France that were not then parties to the NPT, established the Nuclear Suppliers Group to better control nuclear commerce intended for peaceful purposes. In 2004 the group had 40 members and had gradually tightened the group’s common export control rules.

C -Nunn-Lugar Program
The breakup of the Soviet Union in late 1991, which brought an end to the rigid controls of the Soviet internal security apparatus and began a period of social and economic turmoil, introduced a major new proliferation threat. This was the risk that portions of the massive Soviet nuclear weapons arsenal might leak to countries or terrorist organizations seeking nuclear weapons. The Soviet nuclear legacy included tens of thousands of nuclear weapons, hundreds of tons of highly enriched uranium and plutonium not yet incorporated into weapons, and many thousands of scientists with expertise in the production of nuclear arms.

To address this threat, in 1991, the United States launched the Cooperative Threat Reduction Program, also known as the Nunn-Lugar Program, after the two U.S. senators who launched the initiative—Democrat Sam Nunn and Republican Richard Lugar. The program, whose budget in the United States is roughly $1 billion annually and which is being matched by similar contributions from other leading industrialized countries, provides monetary and other assistance for Russia. This assistance is intended to help Russia improve security over nuclear weapons and nuclear-weapons material, eliminate excess highly enriched uranium and plutonium, and employ former Soviet nuclear weapon scientists in nonmilitary research activities. Assistance is also provided to other countries of the former Soviet Union to address similar proliferation risks within their borders.

D -Proliferation Security Initiative
In 2003 the United States launched a major new effort to address the threat of nuclear smuggling, the Proliferation Security Initiative. The initiative seeks to aggressively enforce national and international laws to seize cargoes containing equipment and material that could be used to manufacture weapons of mass destruction equipment before they can reach their intended destinations. More than 30 nations are now participating in this effort.

E -UN Resolution 1540 and Other Measures
In April 2004 the United Nations (UN) Security Council adopted Resolution 1540. The resolution requires UN members to implement effective measures to secure within their borders the know-how, equipment, and materials that could be used to make weapons of mass destruction and to adopt effective export controls. This resolution was passed because of growing concerns about terrorist acquisition of weapons of mass destruction and the revelations that a senior Pakistani nuclear scientist, Abdul Qadeer Khan, had sold uranium enrichment equipment to Iran, Libya, and North Korea and a nuclear weapon design to Libya and possibly the other states.

Many other measures have helped slow proliferation. Under some military alliances, such as the U.S.-led North Atlantic Treaty Organization (NATO), for example, nuclear weapon states promise to extend protection to nonnuclear weapon states, making their development of independent nuclear arsenals unnecessary. Concerned nations can also direct intensive diplomatic and economic pressure—including public criticism, breaking off relations, or imposing trade embargoes—against states seeking nuclear weapons. Such efforts have led some target countries to abandon these programs. Libya’s renunciation of weapons of mass destruction in 2004 was partly the result of such efforts.
VII -PROBLEMS AND ISSUES IN NONPROLIFERATION EFFORTS

A-Nuclear Smuggling
Efforts to curb nuclear proliferation face a series of major new challenges. First, the nuclear smuggling network established by Abdul Qadeer Khan demonstrated that proliferation can be actively assisted not only by national governments, as in the past, but also by private, nonstate persons and organizations that have access to key knowledge and equipment. Khan’s sale to Libya of all the key elements needed to build a gas centrifuge uranium enrichment plant and his sale of a proven nuclear weapon design was unprecedented. Khan appears to have transferred most, if not all, of these to Iran and North Korea, as well.

In addition, Khan’s network established machining shops in Malaysia and perhaps in other locations to manufacture key centrifuge components, making these activities extremely difficult to detect for foreign intelligence services seeking to slow proliferation. It is not known whether elements of Khan’s network still survive and how many customers may have received copies of highly sensitive documents. These nonstate actors are far less visible and can be far more difficult to influence than nations, which can be pressured diplomatically, or threatened militarily, to change their behavior.
UN Security Council Resolution 1540 will encourage states such as Pakistan and Malaysia to better control activities related to weapons of mass destruction within their borders and to prevent improper exports. The effectiveness of this new element of the nonproliferation “regime” remains uncertain, however.

The IAEA is also encouraging NPT nonnuclear weapon states to give the agency broader inspection authority under an additional protocol to their basic inspection agreements with the agency. The new authority will give the agency the right to demand access to any site in a country where the agency believes activities related to nuclear weapons development may be taking place. This authority, if widely granted, could significantly restrict future nuclear smuggling networks.

B -Secret Activities
A second challenge is the growing number of cases in which countries have pursued secret activities that violated the NPT and were not detected by the IAEA. In early 2002, for example, the international community first became aware that Iran was pursuing a major gas centrifuge uranium enrichment program, including a pilot enrichment facility, a gas centrifuge manufacturing plant, and early construction of a large-scale enrichment plant. In 2004 Libya’s secret acquisition of uranium gas and of a portion of the equipment for a similar gas centrifuge facility was also revealed. Similarly, in 2004, South Korea’s previous experiments with laser isotope enrichment came to light.
All of these countries were parties to the NPT and were obligated to place all other nuclear materials (and facilities using such materials) under IAEA inspection. They were also required to disclose plans for the construction of new nuclear facilities to permit the agency to verify their design. None of these states, however, complied with these requirements. The IAEA was unaware of this situation, and so apparently were foreign intelligence services. The episodes raise serious questions about the effectiveness of key parts of the international nonproliferation system.

The widespread acceptance of enhanced IAEA inspections by NPT nonnuclear weapon states through the signing of additional protocols could go far toward addressing this challenge. Since the disclosure of its uranium enrichment program, for example, Iran has permitted the IAEA to use the new inspection techniques. This has allowed the IAEA to uncover many new details about the previously secret program. Strict IAEA inspections in that country have been strongly supported by the agency’s member states through the IAEA Board of Governors, an essential element of efforts to enforce IAEA rules, which may bolster the agency in future cases. In late 2004, as the result of information uncovered by IAEA inspectors and strong international pressure, Iran agreed to freeze its uranium enrichment program, under an agreement with the European Union (EU), negotiated by Britain, France, and Germany.

In February 2006, however, Iran announced that it was resuming its uranium enrichment program. In March the United Nations Security Council issued a statement demanding that Iran cease its program. In April Iranian president Mahmoud Ahmadinejad declared that by using a cascade of 164 linked gas centrifuges Iran had succeeded in enriching uranium to about 3.5 percent, which is suitable only for use as nuclear reactor fuel. The IAEA subsequently confirmed this achievement and said Iran was in violation of the Security Council’s demand to cease uranium enrichment. Ahmadinejad also boasted that Iran had developed a more advanced type of gas centrifuge, known as the P-2, which is capable of enriching uranium much more quickly. The IAEA said Iran had refused to provide details about the program, which the IAEA needs to inspect effectively. Iran continued to declare its support for the NPT, but many proliferation experts and officials in other countries worried that Iran might have a secret nuclear weapons program.

Nonproliferation may also be facing a more basic challenge: Some states may believe that they need nuclear weapons to protect themselves against bullying or military intervention by more powerful states. North Korea has justified its development of nuclear arms as a “deterrent” against U.S. aggression. Iran, similarly, may be developing the option to manufacture nuclear weapons out of concern that, without them, it would be vulnerable to U.S. intervention, as Iraq was.

The United States has attempted to address such concerns. In the case of North Korea, the United States has held discussions on a package of arrangements that might include a nonaggression agreement, diplomatic recognition, and economic assistance. The package would be provided in return for North Korea’s giving up its nuclear weapons program under strict verification. In the case of Iran, the United States has emphasized that it seeks a diplomatic solution to limiting Iran’s uranium enrichment program. Iran has emphasized that its nuclear program is exclusively for peaceful purposes and appears reluctant to withdraw from the NPT. This is an indication that the norm of nonproliferation remains a powerful influence internationally.

C -Nuclear Lobbies
Another challenge to nonproliferation comes from individual scientists and nuclear-related organizations within individual countries that are strong champions of nuclear weapons development. Pressure by such groups is believed, for example, to have led India to conduct a series of nuclear tests in 1998, reversing the country’s no-nuclear-test policy of 24 years. In states with existing nuclear arsenals, the desire to sustain budgets and influence can lead organizations to oppose arms reduction initiatives. Advocates of nuclear exports in some states can also lead to governmental decisions that some argue promote proliferation, such as Russia’s decision to help Iran build a nuclear power plant at Būshehr.

In most nations, however, advocates of policies of nuclear restraint counter these pressures. In Libya, for example, those promoting the country’s secret uranium enrichment program were overruled by others who believed it was wiser for the country to renounce weapons of mass destruction and become accepted as a valued member of the international community. Initiatives by outside countries to curb proliferation can take advantage of these different perspectives within nations, by emphasizing the advantages such nations will enjoy by remaining non-nuclear weapon states—and the penalties they may suffer if they pursue nuclear arms.

D -The Terrorist Threat
Among the most dangerous proliferation challenges is the threat that a terrorist organization might acquire a nuclear weapon or the highly enriched uranium or plutonium that would allow it to manufacture one. Given the unrestrained injury some terrorist groups seek to inflict upon their enemies and their disregard for their own survival, it must be feared that a group, such as al-Qaeda, would use a nuclear weapon, causing catastrophic harm. Preventing this outcome requires rapid completion of efforts to secure nuclear weapons and nuclear weapons materials worldwide, particularly in Russia, through cooperative threat reduction programs.

VIII -DISARMAMENT
Nuclear disarmament appears a very distant and, possibly, unachievable, prospect. Nonetheless, at least one country, South Africa, has taken this step, Libya has chosen to end its pursuit of weapons of mass destruction, and Iran insists that, although it will pursue its uranium enrichment program, it will not develop nuclear arms. Negotiations with North Korea may ultimately result in the elimination of its nuclear weapons. Thus, despite current challenges, international nonproliferation efforts have accomplished much, even if the record is far from perfect.