The control of nuclear weapons so far

It is nigh 65 years since the evolution of the first nuclear bomb, and however we have had just two cases of use of nuclear weapons in war, namely Hiroshima and Nagasaki. Then we have been spared the horror of a large nuclear war during this period when more than 130,000 nuclear weapons were built. This is a very unusual outcome in the history of mankind: and so many weapons built, never to be used. Why has this happened? Outset, the leadership of the two nuclear superpowers and of the smaller nuclear States behaved every bit rational conclusion makers, as far as the command of nuclear weapons and the determination not to initiate their use were concerned. In others words, deterrence worked, simply we have to recollect that the Cuban missile crisis of 1962 and other bottom crises pushed the hazard of a nuclear confrontation very close to the completeness. Moreover, the arrangement of nuclear deterrence worked and withal works at present on the footing of the capability of each nuclear superpower to react promptly if they receive information that they are under nuclear missile attack from their opponent. The thought is that each nuclear superpower should react confronting the opponent before its own nuclear missiles are destroyed while however on the ground or in their silos. With this system, known as nuclear reaction alarm or "launch on warning", we have had numerous incidents of fake assault that risked accidental nuclear war. Among the factors that spared mankind from the horror of a nuclear war, one was adept luck, in not taking wrong decisions at critical moments, and in keeping technical mistakes and failures ultimately under control.

We know that the probability of having a catastrophic upshot depends on the number of disquisitional events: the higher the number, the higher the probability. In our instance, the probability of a nuclear conflict depends clearly on the number of crises which could peradventure induce a nuclear state of war and on the number of technical failures of the nuclear control systems. These numbers in turn depend on the number of existing nuclear arsenals, on the number of nuclear weapons in those arsenals, and on the number of people who take access to the nuclear button.

In avoiding a nuclear catastrophe we have been helped by the fact that contrary to the expectations of the early nuclear age, most nations have remained non-nuclear; in other words proliferation was contained.

The non-proliferation government

The basic instrument which helped comprise the spread of nuclear weapons is the 1968 Treaty on the Non-Proliferation of Nuclear Weapons (NPT), more often than not considered to be the corner-rock of nuclear stability. The NPT distinguishes its parties betwixt nuclear-weapon States (NWS) (States which conducted a nuclear test before 1967) and all the other States that, in club to be a member of the NPT, are classified every bit not-nuclear-weapon States (NNWS). The Treaty has basically three pillars:

The Principle of Not-Proliferation: The not-nuclear-weapon States refrain from acquiring nuclear weapons or from seeking the control of nuclear weapons, while the nuclear-weapon States agree not to transfer nuclear weapons or parts of them to others. Moreover, all Parties to the Treaty should refrain from transferring (un-safeguarded) fissile fabric to non-nuclear-weapon States.

The Principle of Disarmament: Parties to the Treaty, and particularly the nuclear-weapon States, commit themselves to negotiations in skilful faith aimed at achieving an early stage nuclear disarmament and the cessation of the nuclear arms race.

The Principle of Access to Peaceful Nuclear Technology: All Parties to the NPT accept the right to develop and exist assisted in the development of nuclear free energy for civilian purposes.

The cold war ended with a significant attempt in the management of nuclear disarmament. Between the 2nd half of the 1980s and the beginning of the 1990s, the United States and the Russian Federation dramatically reduced the size of their arsenals. Moreover, for some time effectually the cease of the cold war, no not-nuclear State decided to acquire nuclear weapons, leaving the set of countries possessing nuclear weapons unchanged, namely the five permanent members of the Security Quango -- Communist china, France, Russian Federation, United Kingdom and United states of america -- and -- unofficially -- Israel. The Chernobyl accident in 1986 sparked a negative picture show of civilian nuclear activity, and for some time, interest in nuclear energy dropped worldwide, as did interest in proliferation problems associated with the nuclear fuel cycle and the spread of nuclear energy technology. The NPT itself was extended indefinitely in 1995, contributing to what seemed to be a bright prospect for nuclear non-proliferation and disarmament.

Managing disarmament and non-proliferation in the terminal 2 decades

In the mid-1990s, the three pillars of the NPT experienced a pregnant shift. First, the Russian Federation and the US basically froze their disarmament agenda, with the last signed treaty leaving some ane,700 to 2,200 deployed strategic weapons on each side and an unspecified number of tactical, as well equally other retired -- merely not destroyed -- nuclear weapons on each side. Moreover, the other, smaller, nuclear powers, French republic, the People'southward Republic of China, and the Great britain, stood articulate of the consummate nuclear disarmament threshold. The total number of performance nuclear weapons remained and all the same is in the range of 25,000. In 1998, two newly alleged nuclear powers arose -- though unofficial from the standpoint of the NPT. And afterward, for the offset fourth dimension, one country, the Democratic people's republic of korea (DPRK), exited the NPT and conducted a nuclear examination.

Moreover, some remarkable initiatives -- such every bit the adoption of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) prohibiting nuclear tests hence hindering the development of new types of nuclear weapons -- basically failed to become a reality, thus contributing to the feeling that the era of nuclear disarmament concluded. Some other of import initiatives [such as the 13 steps] aimed at reinvigorating nuclear disarmament, were discussed and approved at the 2000 NPT Review Conference, just were not even mentioned in the 2005 NPT Review Conference, which ended without any terminal document. Finally, an interest in civilian nuclear energy returned in various parts of the earth. Questions about the possibility of an constructive command to prevent the covert utilization of civilian technology for war machine purposes became more and more relevant; the International Atomic Energy Agency (IAEA) in Vienna elaborated stricter constraints to be applied to countries developing civilian nuclear programs, notably the so-chosen "additional protocol".i These stricter constraints have been received with mixed responses. Many countries critical to proliferation risks declined to sign the additional protocol. One specific country has been under extensive scrutiny and has been accused of developing an ethnic fuel bicycle with the undeclared purpose of taking steps frontwards in the direction of edifice nuclear weapons.

In article Half-dozen of the NPT, explicit mention is made not just to nuclear disarmament as a last goal, but also to the pursuing of negotiation leading to an early cessation of the arms race amidst nuclear powers, as an intermediate step. Contrary to this we accept seen in the past 2 decades worrisome signs of the unraveling of the arms control regime equally we know it. The cessation of the Anti-Ballistic Missile (ABM) Treaty; the threat by the Russian Federation to withdraw from the Intermediate Nuclear Forces (INF) Treaty in response both to the new proposed deployments of missile defence systems in Europe past the U.s.a., and to the increased intermediate range missile capabilities in many Asian countries -- all present a gloomy picture of the condition of the arms control government.

 It is thus clear why the NPT is increasingly considered to exist in critical condition.

No state supports nuclear proliferation. No government is buying the statement that "more than is meliorate" when speaking most nuclear-weapon States, but individual countries may decide that they need to possess nuclear weapons. Moreover countries differ in the strategy for enforcing not-proliferation, and in their individual perceptions of the threat posed by unlike cases of proliferation.

Countries may decide that they desire to acquire nuclear weapons for two basic reasons:

1. The presence of an external threat, peculiarly, simply not exclusively, when the external threat is represented by nuclear-weapon States (whether official or de facto).

2. The prestige and the power which is associated with nuclear weapons.

The NPT up to now has done a remarkably good chore in inducing countries to refrain from the acquisition of nuclear weapons by addressing, admitting in an imperfect mode, both of the above motivations. The principle of non-proliferation in the NPT helps in creating an surround partially free from nuclear threats, while the principle of disarmament aims at decreasing both the relevance of nuclear weapons and the prestige associated with their possession. The NPT, as is well known, discriminates between the haves and the accept-nots. This discrimination was meant to be temporary, equally it was understood that the only manner to move towards a stable equilibrium would be to resolve the distinction between the haves and the have-nots past eliminating nuclear weapons, namely, by making them illegal as in the case of chemical and biological weapons. Advancing towards such stability is tantamount to having manifest, unequivocal and sustained progress in nuclear disarmament.
The lack of disarmament initiatives is not the only way the not-proliferation regime has been endangered by the nuclear- weapon States. One of the nearly meaning problems facing the NPT is that some nuclear-weapon States, most notably the US, accept sidetracked the NPT, while paying formal tribute to its office; their fight confronting proliferation took a more unilateral approach and included the post-obit points:

♦Nuclear proliferation threatens the present system of international relations, merely serious differences have to be considered depending on who is in fact acquiring or attempting to acquire nuclear weapons. Some States were very bad nuclear proliferators and others were considered non then bad. The relatively good ones like State of israel and Bharat of class have been treated very differently from the so-called bad ones.
♦Progress in nuclear disarmament has not been deemed to take de facto influence on the decision of another land to acquire or not to learn nuclear weapons. Token reference has been made to previous achievements in nuclear disarmament, but with little or no outcome on the political decisions that are to be taken.
♦ The fight confronting proliferation has been primarily based on containment and repression of countries that take been deemed to exist both hostile and possible nuclear proliferators. Instruments of repression ranged from unlike types of sanctions to actual (preventive) war.
♦ The need to control fissile material and to foreclose its unauthorized use by potential proliferators or terrorists has been acknowledged in principle, although questions arose as to their actual position on the priority list to prevent the spread of nuclear weapons.

Let u.s.a. elaborate more on the tendency described above and on its consequences. One should not underestimate the caste of resentment that has been induced past real or perceived unfair treatment, and the ensuing political consequences. Israel was not subjected to whatsoever pressure to renounce its possession of nuclear weapons. Bharat and Pakistan were subjected to sanctions, which were after removed. In the end India and the Usa signed the then-called US-India Nuclear Cooperation Initiative. DPRK, which withdrew from the NPT, is nether severe sanctions. While we practice not desire to deny here that in that location may be serious motivations and reasonable considerations backside these unequal treatments, the overall impression is however that nuclear disarmament lost its character of beingness a shared ideal or value of the international community and instead became one of the many instruments of partisan strange policy. We should think that the NPT itself was not meant to involve only countries with common foreign policy goals, but rather it was an agreement amongst countries with different, if non antagonistic views of the world, which agreed to some mutual constraints in the area of nuclear weapons.

While it is true that there is no immediate correlation betwixt the pace of nuclear disarmament by major nuclear powers and the development of nuclear ambitions among non-nuclear-States, information technology is also true that if a general trend supporting nuclear disarmament is in place, then the global environment is less threatening to potential proliferators, who would discover it more difficult to become nuclear without losing credibility and influence. While the lack of disarmament may not exist the immediate motivation for proliferation, information technology notwithstanding has an overall influence on encouraging proliferation. In other words, if nuclear powers keep telling others to "do as I say and not as I do", in that location is no guarantee that this message will be listened to indefinitely.

Creating an environment where powerful countries impose independent, autonomous non-proliferation constraints might even be considered necessary to effectively limit the transfer of dangerous nuclear technology and materials. 1 might thus capeesh a complementary role between individual countries and international institutions in the battle against proliferation (encounter the Proliferation Security Initiative (PSI) or Security Quango resolution 1540). Problems arise when the non-proliferation campaign is used as an excuse to impose sanctions or wage war against a country that is labelled evil, and where the main aim is not to finish proliferation but to induce a regime change. The problems become bigger if the intervention does not event in the restoration of peace and lodge but in the creation of civil unrest. Even if we have no fourth dimension to address the complexity of the bug related to the final disharmonize in Iraq, we want to point out that, from the point of view of nuclear proliferation, the Iraqi war had the effect of greatly diminishing the significance of the non-proliferation issue, reducing it to a mere excuse for another goal. Moreover, the war on Republic of iraq sent two other sets of messages: commencement, that big powers can featherbed international institutions such as the UN; and second, that countries much closer to reaching military nuclear capability are punished far less than countries which are classified as "evil" only are further away from that capability. This mental attitude creates an objective incentive for nuclear proliferation.

The nowadays prospect for managing non-proliferation and disarmament

Since 2008 and, after, with the climate created by the new US assistants, a dissimilar approach to disarmament and non-proliferation has begun to appear. A grouping of four prominent American former loftier level officials published on thirty June 2009 a widely read article in the Wall Street Journal2 followed by groups of politicians in some European countries,3 all arguing for a renewed call for nuclear disarmament. On 5 April 2009 President Barack Obama said: "I state clearly and with confidence America's commitment to seek the peace and security of a world without nuclear weapons." He as well restated clearly the goal of the NPT: "Countries with nuclear weapons will movement towards disarmament, countries without nuclear weapons will not acquire them, and all countries tin access peaceful nuclear energy".4 At present at that place is a articulate interest in the United states assistants to restart dialogue with Russia over the renewal or replacement of the Strategic Arms Reduction Treaty (START) and brand further progress in arms control and disarmament.

Expectations will run loftier at the 2010 NPT Review Conference. Either there will be a very articulate message that the three basic pillars of the NPT should be rigorously respected viz., that disarmament should not be disconnected from the enforcement of non-proliferation; and that assistance to develop nuclear free energy should be given without undue restrictions or discriminations, yet within a framework of serious and effective monitoring and control of nuclear activities, or the non-proliferation regime itself risks serious problem. The entire international community and particularly the nearly powerful countries such equally the G8 -- Canada, France, Germany, Italy, Japan, Russian federation, United kingdom of great britain and northern ireland, United states of america -- should take steps to preserve the essence of the NPT, and to make it more constructive and stable every bit President Obama suggested in his speech in Prague.

What follows is a listing of bug that should or could be addressed, and a listing of steps that should be undertaken by the unabridged international community in preparation for the 2010 NPT Review Conference. Obviously the responsibilities of States vary according to their involvement with military or civilian nuclear programmes For instance, the arms reductions of the US and the Russian federation concern those ii States just. Still it is of import that the physical actions aimed at developing disarmament and at curbing non-proliferation be included in a framework strengthening all the obligations that are at the basis of the NPT. All countries could and should contribute to this framework.

Nuclear-weapon States should reduce their nuclear arsenals to the "minimum" possible level. This line of thinking has been already made articulate by the Presidents of the US and the Russian federation. Some of the concrete decisions in this expanse volition become articulate when a replacement of the START Treaty is discussed. Together with the reduction in nuclear weapons, there is the problem in the role or the salience of nuclear weapons in military planning. The key phrase hither is to de-emphasize the role of nuclear weapons in armed services planning. Also nuclear weapons should exist taken off alert: no nuclear weapon should be launched inside minutes of notification of a missile attack. Avoiding a nuclear war by error is a task as of import as ever.

♦ The development of the Ballistic Missile Defense force should be carefully considered. If the effectiveness of such systems is, every bit it appears, to exist highly doubtful then countries should exist very careful with the political and strategic implications of the deployment of such systems. Information technology is not worth jeopardizing the reduction of nuclear weapons and the preservation of by arms control agreements, past deploying defensive systems of very dubious effectiveness.
♦Tactical nuclear weapons should clearly be included in the list of nuclear weapons considered for reductions and/or elimination.
♦ Eliminated weapons should exist destroyed or dismantled. They should not be put in deposits and left ready to be used should there be a need to again increase those nuclear arsenals.
♦The problem of nuclear weapons deployed on other countries' territories should be carefully considered. Merely Us nuclear forces are currently deployed in other countries: Kingdom of belgium, Germany, Italy, the Netherlands, Turkey. Other official or de-facto nuclear powers might in the futurity decide to do the same, creating the possibility for very dangerous situations. It is then reasonable to preclude deployment of nuclear weapons on other countries' territories.

♦Nato should de-emphasize the role of nuclear weapons in its war machine planning and strategy.

♦The entry into strength of the CTBT is bound to the ratification by 44 specific countries (Annex ii of the Treaty). The entry into force of the treaty will give a powerful signal to the international community that no further modernization of nuclear weapons will exist possible. The countries that should sign and ratify Annex 2 are India, Islamic republic of pakistan and the DPRK. The countries that should ratify the Treaty are: Communist china, Arab republic of egypt, Republic of indonesia, Iran, Israel and the U.s.. The new U.s.a. assistants is clearly supporting the ratification of the CTBT, but it may have problems with the Senate as the ratification procedure requires a qualified majority of the US Senate. The international community should encourage the missing Annex ii countries to sign and ratify the CTBT. As for the nuclear-weapon States, their technical activities to ensure weapons reliability should not interfere with the CTBT. This is technically possible and warhead reliability issues should not be used as a motivation to postpone or sidetrack the CTBT.

♦Another important instrument for pushing alee the agenda of nuclear disarmament is the Fissile Cloth Cut-off Treaty (fmct) that will forestall the production of new fissile material for military purposes.

♦It is credible that all the 5 nuclear countries irrespective of the size of their arsenals, viz., the US, the Russian Federation, China, France and the UK share a legal and political responsibility in promoting disarmament, and none of them should be exempt from taking advisable steps in the management of reducing their weapons and their reliance on them.

♦Nuclear-weapon States that are not signatories to the NPT (Bharat, State of israel and Islamic republic of pakistan) and the DPRK should exist induced to have advisable steps to reduce their reliance on nuclear weapons and the number of their weapons; to sign all the possible arms control agreements compatible with their status as non-NPT members; to enforce strict command of nuclear material, respecting all the relevant agreement with the IAEA, and ultimately to join the NPT.

♦Finally the cosmos of new nuclear-weapon-free zones (NWFZ) and the expansion of the old ones is an important instrument to forestall the introduction of nuclear weapons in specific areas. The Middle Due east nuclear-weapon-free zone should exist constantly pursued, despite the obvious difficulties.

The possible use of nuclear weapons for terrorist purposes has been discussed for some time. Fortunately, upwards to now, no possession of nuclear weapons by terrorist groups has been detected and no terrorist group has been able to manufacture a nuclear explosive device.5 The proper strategy to address potential nuclear terrorism is to reduce the relevant risks. First, by controlling all fissile material and eliminating backlog fissile cloth from dismantled weapons (ie, blending the excess of highly enriched uranium and disposing and/or utilizing in mixed oxide in the excess plutonium). 2d, it is important to get the agreement of all States, irrespective of their political orientation, to control any corporeality of fissile material produced with the strictest bachelor safeguards. The international community is lagging behind on both counts. There is nonetheless a big amount of backlog fissile material to exist disposed of mainly in the Russian Federation (about xx years after the INF Treaty) and, as mentioned above, international consensus most new stringent measures to control nuclear activities is still relatively express. In any case, international control (by the IAEA) does not business organization fissile material for war machine employ. The causes for this state of affairs are manifold, from commercial issues, which slowed the disposal of fissile material in the quondam Soviet Union, to the perception that stringent safeguards are at times an musical instrument of discrimination rather than an instrument aimed at protecting the security of every land. Failing a vigorous effort -- both technical and diplomatic -- to control and dispose of fissile textile, the threat of nuclear terrorism volition be with us for some time. Once again, i has to wait that the new US assistants will exist very sensitive to the argument of controlling nuclear material and protecting it against terrorist utilise, but the brunt goes well beyond the US and is, in fact, a responsibleness of the entire international community.

The final issue nosotros accept to discuss is the problem of preventing proliferation. As mentioned earlier, an effective battle against nuclear proliferation cannot exist separated from clear progress towards disarmament. Another important signal to consider is that the battle against nuclear proliferation will be much more effective if the constraints required to enforce control and monitoring of nuclear activities will be seen as an impartial musical instrument required past the international customs, not as an instrument aimed at discriminating between various countries on the ground of their political or strategic orientation. As we said before, the NPT was built-in as an understanding between States having a very different vision of the world. In the NPT, the U.s. cooperated with the USSR in keeping proliferation under control and, for some time, in dramatically reducing the nuclear arsenals. Unlike visions of the world did non impede the NPT from working; this should be true even now when States antagonistic to the The states are not as powerful as the USSR was, but may still in general be unlikely to yield to pressures.

Fairness and non discrimination (beyond the accustomed bigotry between nuclear and non-nuclear States equally divers past the NPT) should be the key to the safe preservation and improvement of the not-proliferation government.

In order to improve the collective security in nuclear diplomacy, there is an urgent demand to revisit the safeguards and constraints placed on the production of fissile material. The "additional protocol" not still adopted by a sufficiently large number of States is probably not enough, and more stringent, international control on the production of fissile material for noncombatant purposes should be established. New ideas along these lines have been put forward by the IAEA, in particular equally far every bit the internationalization of the nuclear fuel wheel is concerned, simply more ideas are needed. IAEA membership could easily become universal, as even countries outside the NPT are members of the IAEA. There is moreover no objective reason why all countries which are members of the IAEA should non exist induced to sign and ratify the additional protocol and other stringent measures, without exception.

The IAEA should be strengthened and positioned to perform what looks to be an increasingly wider and enervating activity in the command of nuclear activities.

The upshot of addressing alleged violations of the non-proliferation rules came up in the past and will most likely come up again in the time to come. The principle should be articulate: violations should exist met with sanctions aimed at reversing the behaviour that originated the violations. The civilian benefit derived from NPT membership should be revoked from violators and mayhap the use of force could be considered. Problems arise when sanctions are unfair, when credibility of "international justice" is low and when the definition of the alleged violations of the non-proliferation rules go mixed with other political or strategic controversies. Soft approaches may be better suited than hard pressures, but there is no full general dominion. Dialogue may be very difficult at times, just tin go a long style and should be the principal musical instrument for resolving disputes. The effectiveness of sanctions depends on many factors: long-term large-scale sanctions, for example, are generally less effective, equally countries tend to arrange to a prolonged sanction government. The resulting isolation fosters nationalistic attitudes and cuts off the political and economical leadership from the international loonshit. Moreover, authoritarian regimes tend to exist strengthened by isolation and, if at that place is a conclusion to build nuclear weapons or weapons of mass destruction, sanctions strengthen nuclear ambitions.

War machine force has recently been used confronting countries suspected of violating the non-proliferation rules. Leaving aside for a moment the important outcome of the legitimacy of these actions, the results accept been altogether a failure. In general terms, information technology may be truthful that some military deportment slow downward the construction of nuclear weapons or weapons of mass destruction by destroying some specific infrastructure, but so what comes next? If, after the devastation of some specific nuclear infrastructure, the country is able to restart the programme, and so nothing has been "gained", except possibly some time. And if military machine pressure on that land goes well beyond the destruction of nuclear plants, then the recent history of Iraq shows that the finish result may create an intractable problem.

Conclusions

Facing the 2010 NPT Review Briefing there is a need to strengthen the iii pillars of the NPT itself. Nuclear disarmament should be pursued in a clear way past all nuclear-weapon States. Additionally, monitoring systems should be improved for all civilian nuclear activities, without further discrimination with respect to those that are already within the NPT. The evolution of nuclear energy should happen in a framework that must guarantee and strengthen security for all and foster a sense of commonage responsibleness.

It is a articulate task of the well-nigh adult countries to lead the international customs towards a more cooperative and less discriminatory surround, where the danger of nuclear annihilation will be drastically reduced and ultimately brought to zero. Nuclear weapons should presently be alleged illegal as much as all the other chemical and biological weapons of mass destruction are. This will require a nuclear weapons convention similar to the chemical and biological weapons convention. Countries should clearly and unequivocally practice their best to bespeak that they are moving in that direction.

This article is an adaptation of a presentation prepared for ISPI (Istituto Studi Politica Internazionale) of Milano, Italy and get-go published in the Un Chronicle.

Notes
1. The boosted protocol: http://www.IAEA.org/Publications/Documents/infcircs/1997/infcirc540c.pdf

2. Kissinger, Nunn, Perry, Schultz : http://online.wsj.com/commodity/SB120036422673589947.html?mod=opinion_main_commentaries

3. Douglas Hurd, Malcolm Rifkind, David Owen and George Robertson, "START worrying and acquire to ditch the flop" The Times (London), 30 June 2008. (http://world wide web.timesonline.co.uk/tol/comment/columnists/guest_contributors/article4237387.ece )

F.Calogero, M. DíAlema, G. Fini, G. La Malfa, A. Parisi, "Towards a Nuclear-Weapon-Free World", Il Corriere della Sera, 24 July 2008.

Helmut Schmidt (SPD), old High german President Richard von Weizsäcker (CDU), sometime Foreign Minister Hans-Dietrich Genscher (FDP) and SPD politician Egon Bahr, Frankfurter Allgemeine Zeitung and International Herald Tribune, ix January 2009.

Field Marshal Lord Bramall, General Lord Ramsbotham, Full general Sir Hugh Beach, "Uk does not demand a nuclear deterrent: Nuclear weapons must not be seen to be vital to the secure defence of self-respecting nations", Letter, The Times (London), 16 Jan 2009 (http://www.timesonline.co.uk/tol/annotate/letters/article5525682.ece)

4. Prague speech http://world wide web.huffingtonpost.com/2009/04/05/obama-prague-voice communication-on-nu_n_183219.html

5. Often confusion is fabricated between a so-called dirty flop (which entails the dispersal of radioactive fabric in the surroundings) and a nuclear explosive device, where the explosion is acquired by a nuclear concatenation reaction. Nosotros bargain only with the possibility of terrorists acquiring or building nuclear explosive devices.