Nuclear Weapons Systems Research Articles

Prestige and punishment: Status symbols and the danger of white elephants

This article identifies and unpacks the intrinsic potential for backlash in the pursuit of status symbols. While status loss has been associated with domestic pushback and reduced legitimacy for ruling governments, the literature on status is yet to examine how status-seeking can backfire even when a state can successfully claim to have acquired a status symbol. We contend that status backlashes are an inherent risk of status-seeking due to the multivocality of costly status symbols. Our heuristic framework for studying status backlashes proposes examining modes of critique that construe status symbols as irrational or unjustified costly endeavours, undermining their legitimating capacity and potentially even transforming them into a marker of stigma. Empirically, we identify three modes of critique present in reactions to Brazil’s hosting of the World Cup in 2014 and the Olympics in 2016. There, despite recognizing the symbolic value of hosting these mega-events, Brazilian audiences also criticized the government for the opportunity costs, vested interests and subservience that it entailed. Undertaking two shadow case studies – on the backlash against the United Kingdom’s renewal of its Trident nuclear weapons system and Norway’s engagement in military interventions between 1999 and 2012 – we document how these modes of critique associated with status symbols can travel across contexts.

Epistemology in AI (Transdisciplinary AI)

A critical look at the evolution of AI strongly shows a sustained but stealth race to replace humans with AI. Early scientific literature and discourse on AI for some reasons (either to allow AI gain entry and acceptability in mainstream scientific and technological arena) vehemently deny this "human replacement agenda". This thinking pattern unknowingly shaped current scientific literature, discourse, general understanding of what AI is and its development and applicability (a reductionist thinking). This limits our understanding in both the beneficial and destructive capabilities of AI. But when considering a TD assessment on the developmental dynamic of AI, one would comfortably say and must be bold to admit, that indeed AI intends replacing humans and is on course for fulfilling this.
 
 We see this AI human replacement agenda in intensified R&D efforts dedicated to developing powerful AI system of systems which massively augment human reasoning, most times far better. The inexhaustible list includes the AI replacement of formerly considered human-centric jobs, advanced autonomous weapon systems, killer robots and AI in warfare, intelligent facial recognition, biometric monitoring, integrating AI on biological, nuclear and space-based weapons systems, etc. If this is the direction AI is taking, then a secondary aim would surely arrive at integrating epistemology in AI or "grant spirits" for AI systems. This is because a distinctive characteristic of a human is his spirit and one cannot replace humans with AI without creating proportionate or appropriate spirits for the AI systems. Sooner or later our AI systems would have epistemological functions and possess spirits. The place of the soul for such AI systems would be attained as well. If human knowledge, beliefs, voices, clips and laws can be preserved long after they are gone as is possible in smart digital technologies, then spirit-based AI would indeed cause these humans to live forever. If the feat of a spirit enamored AI is near, then why worry? Indeed when considering that humans possess good and bad spirits (from the epistemology of rational and irrational inertia) then these AI systems would of course have good or bad spirits and be bad or good AI.
 
 Would integrating a spirit into a rule-based or machine learning algorithmic structure of an AI system have benefits? Yes!, profound benefits too. A spirit-based AI would of course make possible the "possession of feelings" by AI systems, a feat unattainable in both algorithmic, operational and inferential basis of AI systems today. This inability of AI systems to have feelings has continued to remain a major setback in the acceptability (indeed trust) and utilization of AI. As we agree that the spirit in AI is possible, then overlooking efforts aimed at making this possible or allowing AI to attain this level unhindered (admitting dangers of human involvement in AI) could pose a dangerous threat which can become highly destructive to mankind. This calls for critical supervision (TD-based ethical policing) and the accompanying of the evolution, development and applicability of AI hence venerating the need for human mediation in AI both as a major TD research subject and applicable function.
 
 A discussion would be made on my approach which considers the synergy of critical systems heuristics (CSH) and systems engineering (Transdisciplinary Systems Engineering) to create "Transdisciplinary AI" which would formulate methods of integrating "human" epistemology in expert systems. Human epistemology is emphasized because by the maturity of this future nature of AI, there would be terms known as "AI or machine epistemology" or "AI or machine spirits". The investigation begins with creating expert systems (knowledge-based systems) with these functions with plans of moving into robotics and other machine learning arena. Finally, to move the needle on what is considered permissible epistemology or permissible spirit of/in AI is a critical component of the study of human mediation and AI which must be given critical attention. This would be discussed as well.

Just Warfare: Is a Nuclear Attack an appropriate Response to a Cyber Attack?

It is well known that nuclear weapons pose a grave threat to humanity because of their destructive power and to the lives of innocent civilians potentially affected by them. What might be less known are the grave effects that cyberwarfare can potentially have on a state and its nuclear security. Most nuclear weapons systems were designed decades ago, when manipulations of computer networks, or cyber-attacks, were practically a non-existent threat. In the present international political situation, where threats about the use of strategic nuclear weapons, have been discussed, cyber threats are everywhere, and it may be expected that they will have consequences for the stability of nuclear weapons systems as well. Considering the many unknowns of the continually evolving issues related to cyber threats, it is hard to measure how serious the risks are, but the idea cannot be excluded that, over the long term, they may have “game-changing” effects on the perceived value of nuclear weapons. Potential consequences of this phenomenon include cyber operations targeting nuclear weapons development, nuclear weapons systems, and cyber operations replacing nuclear weapons.
 It is crucial that nation states, such as for example the United States, work hard to prevent cyber-attacks in a world where we are becoming more reliant on computer systems that if disrupted could destroy the economy, politics, and even military operations. The question, of how far states are willing to go to protect their cyber realm, and the extent to which their nuclear policies might allow for the possibility of a nuclear response to a cyberattack, present significant issues. This analysis will employ distinctions from just war theory, to attempt to address these issues. Just warfare is important to this analysis because developing a sense of right and wrong in a case of unpreventable conflicts could avoid further escalation and even more devastating results. In other words, what occurs when we apply the ethical distinctions of Just War Theory, to Cyber Attacks related to nuclear weapons? Can the distinctions of Just War Theory be employed to create a taboo, so that, the protection of a states cyber security creates an obstacle so that cyber warfare does not lead to a result such as nuclear attack? This analysis also takes into consideration anticipatory research, while developing an argument based on ethical considerations without a nuclear attack having to occur first. Anticipatory research such as this is important as the foundation for developing preventative measures because it can be used to argue for the creation of policies (both domestic and international) that will not allow for a nuclear response to a cyber-attack, therefore eliminating the threat to the international community.
 This analysis will employ a basic conceptual analysis that will proceed by defining critical terminology and will attempt to address the ethical and anticipated ethical issues related to answering the question, Is a Nuclear Attack ever an appropriate response to a cyberattack?

Nuclear Weapons, Cyber Warfare, and Cyber Security: Ethical and Anticipated Ethical Issues

In this paper, we discuss the interrelationship of nuclear weapons, cyber warfare, and cyber security. Some of the most significant cyber threats to nuclear stability are now due to the intersection of technologies related to nuclear weapons and cyber technology. Cyber warfare can now be used to engage in and influence international events through cyber attacks upon nuclear systems and weapons. In the current war between Russia and Ukraine there has been the threat of the use of nuclear weapons. Since cyber warfare has already been employed in the Russia/Ukraine conflict it is possible that cyber attacks could be employed to trigger a nuclear event. To prevent cyber warfare from leading to nuclear warfare there needs to be a focus on cyber security in order to protect nuclear systems and nuclear arsenals but also to mitigate cyber attacks that could lead to the use of nuclear weapons.
 
 One of the main risks to nuclear weapons systems is sabotage. It is easy to imagine cyber attackers placing incorrect information into systems and even taking control of nuclear weapons. Various parts of nuclear weapons systems are capable of being targeted. Command and control systems, alert systems, launch systems, and target-positioning systems could all become targets. Scenarios in which alert systems are hacked and show a nuclear attack by adversaries, may lead to an accidental nuclear conflict. It is also conceivable that hackers could manipulate the coordinates of (pre-programmed) targets of nuclear missiles, or to spoof GPS-like systems that some missiles use to calculate their positions their targets. At the present time there is no evidence that any state or non-state actor is able to successfully perform such manipulations but considering the exponential rate of developments in the cyber arena, in the near future, such attacks might be possible. In the worst-case scenarios, these possibilities could lead to the inadvertent use of nuclear weapons, and/or use against unintended targets. In less dramatic scenarios, the perceived vulnerabilities of the nuclear weapons systems may affect nuclear stability. This could lead to a decrease in the deterrent value of nuclear weapons. This could come about because potential adversaries may think they have options to manipulate these weapons when being used. It is difficult to forecast the effects of decreasing nuclear deterrence.
 This analysis will define a stakeholder framework for identifying the ethical and anticipated ethical issues with cyber warfare and nuclear warfare and relate these issues to the importance of cyber security. Ethics should be at the center of the discussion of the use of nuclear weapons, nuclear warfare and cyber warfare. Moral concerns should be at the center of the discussion of nuclear warfare. The need for this moral concern is due to the threat to vulnerable populations by nuclear systems and nuclear weapons, as well as the threat posed to democratic institutions by the use of nuclear weapons.

A Neuro-Fuzzy Approach to MOPP Open Time Prediction for Chemical Threats in Low-Intensity Conflicts

Chemical, Biological, Radiological and Nuclear (CBRN) weapon systems hold the potential to cause great damage to a fighting unit. Chemical warfare agents are cheaper and easier to produce and deploy. Mission oriented protective posture (MOPP) equipment is used to isolate soldiers from the toxic environment . Sustained wearing of MOPP overgarments can put soldiers at the risk of dehydration and heat stress. A hierarchal adaptive neuro-fuzzy inference system (HANFIS) model is proposed to predict worst case MOPP open times for surfaces covered with chemical agent resistant coating (CARC) and sand. The model can provide decision support for commanders when determining MOPP open or unmasking time. From HANFIS simulation results it was concluded that the model can accurately predict MOPP open times according to data present in military field manuals, in a manner which is computationally efficient. and easy to interpret based on linguistic rules and most importantly, easy to customize.

ARTIFICIAL INTELLIGENCE AFFECTING STRATEGIC STABILITY

Introduction of artificial intelligence(AI) in the nuclear weapons system exerts the stabilizing as well as destabilizing effect on strategic stability. AI enables informed decision making, development of more survivable delivery vehicle, physical and cyber security of nuclear assets, reduction in possibility of human error, surveillance of compliance of non-proliferation and disarmament treaties, integration of heterogeneous weapons for better performance, and underwater de-mining, etc. Simultaneously, by contrast, the threat to nuclear deterrence and nuclear assets from hypersonic glide vehicle leading to capability race, remote sensing over autonomous surface and underwater vehicles threatening invulnerable second strike capability, Patrov incident like situations possibility and requirement of human interference, instability inherent in threat detection with the deployment of AI driven more survivable and less controllable platforms including UCAVs, UAVs, UUVs, SLBMs, etc. are threatening the strategic stability. Which must be mitigated for long-lasting global peace through the development of universally accepted code of conduct in line with 1949 Geneva convention and Universal declaration of human rights 1948, etc, deliberation for risk reduction in regional as well as global stages, track two and 1.5 diplomacy, enabling human intervention in nuclear weapon launch system, commitment for No first use policy, complex interdependence etc.

How to de-escalate dangerous nuclear weapons and force deployments in Europe

Amidst the war in Ukraine, it is important to raise the prospect and vision of creating mutual security guarantees and ridding Europe of its dangerous nuclear weapon systems and provocative force deployments. In view of reckless Kremlin rhetoric and aggressive military action in Russia’s so-called near abroad, it is time for renewed approaches to arms control. As the Ukraine situation plays out, Russia, the United States, and allies in the North Atlantic Treaty Organization must return to their bargaining tables and negotiate strict limits, verification measures, and overarching controls over their nuclear use doctrines, weapon stockpiles, and conventional force deployments. All sides will have to make deep concessions and de-alert and de-operationalize mid- and short-range nuclear weapons while improving command and control safeguards—because, as we see, brandishing weapons and threatening escalation heightens tensions and increases the danger of crises spiralling uncontrollably.

Understanding Nuclear Postures, Weapons and Technologies in South Asia

Geographic realities and emerging technologies play a significant role in challenging strategic stability. In South Asia, the geographical proximity of India, China and Pakistan is exacerbated by contentious borders, deteriorating diplomatic relations and the mounting collusive Pakistan-China relationship. This dynamic environment merits an analysis of evolving nuclear postures, weapon systems and the development of new technologies, which may challenge strategic stability. Furthermore, tactical nuclear weapons, unmanned weapons and asymmetric warfare, have a tendency to escalate situations and to impact confidence building measures. This essay examines the nuclear postures and weapon systems of China and Pakistan and recommends methods to maintain the status quo. Keywords: emerging technologies, strategic stability, second-strike capability, full-spectrum deterrence, asymmetric warfare

Cybersecurity of nuclear weapon systems

Cybersecurity of nuclear weapon systems

The AI Carbon Footprint and Responsibilities of AI Scientists

This article examines ethical implications of the growing AI carbon footprint, focusing on the fair distribution of prospective responsibilities among groups of involved actors. First, major groups of involved actors are identified, including AI scientists, AI industry, and AI infrastructure providers, from datacenters to electrical energy suppliers. Second, responsibilities of AI scientists concerning climate warming mitigation actions are disentangled from responsibilities of other involved actors. Third, to implement these responsibilities nudging interventions are suggested, leveraging on AI competitive games which would prize research combining better system accuracy with greater computational and energy efficiency. Finally, in addition to the AI carbon footprint, it is argued that another ethical issue with a genuinely global dimension is now emerging in the AI ethics agenda. This issue concerns the threats that AI-powered cyberweapons pose to the digital command, control, and communication infrastructure of nuclear weapons systems.

Space Science & Technology in the Arctic: Promises of Cooperation and Development amid New Security Challenges

Abstract Space science and technology (S & T) holds great potential for international scientific cooperation in the Arctic, especially concerning climate change. Space-based earth observation, navigation/positioning and communication is of great value to Arctic local and indigenous communities. Space-based S & T is also a prerequisite for development of Arctic shipping and natural resources. At the same time, space S & T in the Arctic holds dynamics, which may undermine Arctic and international stability and security. The Arctic houses key infrastructure for nuclear strategic stability, weapon systems, early warning, and ballistic missile defense. Arctic high latitudes provide significant advantages to space S & T with the potential for dual use. Space, which now underpins all societies, may become militarized. Strategic stability safeguards humanity. During the Cold War, there was an effective decision-making process mediated by game theory and modelling. However, new technologies, a far more complex multi-player, multi-nation environment and new space S & T reduce the effectiveness of traditional approaches. This research proposes to address the current intellectual vacuum by creating a clearer understanding of the parameters, players, technologies, and their interactions and develop a new and robust theoretical basis that will contribute in the longer term towards appropriate and balanced Arctic governance for achieving strategic stability and space security. This research will test the hypothesis that Arctic space S & T destabilizes strategic stability and space security. New theory, empirical overview, and modelling will provide a new intellectual basis for governance of Arctic space S & T for strategic stability and space security in the new era.

What's new in the "new" US course towards the DPRK?

The article analyzes the prospects for US-North Korean and inter-Korean relations, taking into account the completed policy review of the new US administration towards the Democratic People's Republic of Korea (DPRK), as well as the results of the President of the Republic of Korea Moon Jae-in’s trip to Washington in May 2021 and his talks with US President Joe Biden. It is concluded that the “new" course proposed by the United States in relation to the DPRK will not lead to a solution to the nuclear problem of the Korean Peninsula and will interfere with the normalization of inter-Korean relations. During his visit to the US President Moon failed to obtain the US consent on ROK more “independent policy” toward North Korea. In spite of lavish investments into US economy and other concessions, Seoul was forced to promise to coordinate his approaches to the DPRK with US and Japan and support US position on Taiwan straits and South China Sea. The author argues that in the current conditions, the introduction of a regime of arms limitation and arms control in Korea should be a necessary stage on the way to complete denuclearization of the peninsula. The transition to a such method of the settlement of the nuclear problem could lead to the resumption of the negotiation process, mutual concessions, including reductions in the level of military-political confrontation, partial or large-scale lifting of economic sanctions in exchange for North Korea's restrictions of its nuclear weapon and missile systems.

Current State of the Russian and US Nuclear Weapons Policies

This article is devoted to the analysis of interaction of the nuclear policy of Russia and the United States in the context of a crisis in bilateral relations, the collapse of the arms control system and the undermining of global strategic stability. First, the authors examine the current state of US-Russian relations in the sphere of arms control. As a result of the US withdrawing from the ABM Treaty, the INF Treaty, and the dim prospects of extending the New START, the authors conclude that the arms control and strategic stability system that was being put together over the course of four decades is in a deep crisis. Second, the authors examine the U.S. nuclear policy and Washington’s efforts to build up and modernize its nuclear capabilities. The 2018 Nuclear Policy Review points to the United States moving away from the principle of no first use of nuclear weapons, lowering the threshold for nuclear weapons use and the desire to maintain options to end conflicts at any stage on terms favorable to the U.S. without a significant risk of starting a general nuclear war. In addition, the authors describe plans of the U.S. military to modernize the nuclear triad. When analyzing the 2019 Missile Defense Review, it is noted that the U.S. desire to ensure its absolute invulnerability to any missile threats, “left of launch” measures to provide missile defense before missile are launched by the enemy, and the integration of defensive and offensive capabilities of missile defense systems confirm the fears of Russia and other countries regarding maintaining their capabilities to conduct a nuclear retaliatory strike. Then the Russian nuclear doctrine is analyzed. The authors reject Western accusations that Russia has the concept of “escalate to de-escalate”, describe the conditions for Russia’s first nuclear use and the specifics of the “retaliatory counterstrike” concept, and also cite Russia's main concerns regarding threats from the US nuclear doctrine and nuclear modernization. We are also talking about the development of new nuclear weapons systems, such as hypersonic weapons, unmanned vehicles and cruise missiles. In conclusion, it is said that the U.S. doesn’t intend to try to maintain strategic stability any longer, Washington’s nuclear strategy has features that are dangerous to international security, which he blames Russia and that Russian fears regarding US nuclear policy are all but legitimate.

The Power of Prestige: Explaining China’s Nuclear Weapons Decisions

ABSTRACTThe majority of the nuclear proliferation literature is dedicated to understanding why states acquire nuclear weapons. While this question remains important, it is also advantageous to push beyond this inquiry to ask what motivates a state’s nuclear decisions after acquisition. Recent research indicates that a state’s nuclear force structure is heavily influenced by its threat environment. But what explains decisions relating to specific nuclear weapon systems? If security is a sufficient explanatory variable, then why would a state pursue nuclear weapons with high development and production costs but relatively low security gains? Using China as a case study, this article explores the power of prestige in explaining such decisions.

'Treatment Not Trident': Medical Activism, Health Inequality and Anti-Militarism in 1980s Britain.

SummaryIn 1985, Britain’s chief group of medical anti-nuclear weapons activists, the Medical Campaign Against Nuclear Weapons (MCANW), launched its ‘Treatment, Not Trident’ (TNT) campaign. TNT called on the Thatcher Government to cancel the acquisition of the Trident nuclear weapon system and divert those funds to the National Health Service and foreign aid instead. Using TNT, this article makes some more general observations about key aspects of the history, nature and ideologies of medical activism in relation to anti-militarism and health inequality. Alongside a conceptualisation of ‘medical activism’, it offers an examination of chief ways in which the strategic mobilisation of health and welfare priorities, and a growing interest in developing nations enabled MCANW to reach a larger audience. Moreover, higher levels of professionalisation, politicisation and inclusivity contributed to TNT’s success, making it a crucial moment in the development of both MCANW and medical activism in general.

The Trump administration’s Nuclear Posture Review

The Trump administration’s Nuclear Posture Review (NPR) apprehends a hostile world due to ‘rapid deterioration of the threat environment since the 2010 NPR’. The new NPR downplays arms control and calls for the modernisation of US nuclear-weapons systems and facilities, as well as expanded nuclear options. The latter would most controversially include low-yield nuclear weapons, which could lower the nuclear threshold.

Democracy versus deterrence: Nuclear weapons and political integrity

This article argues that the practice and performance of nuclear deterrence can never be fully representative or democratic due to the particular pressures placed on leaders by the nuclear condition. For nuclear deterrence to be effective – and for nuclear weapons to have any political value – a leader must always convince both their electorate as well as any possible foe, that they are willing to use nuclear weapons in extremis, irrespective of whether this is their true position. In any nuclear-armed state, where politicians privately believe that using nuclear weapons is always wrong, but publicly stress that possessing nuclear weapons to use as a deterrent is right, they are forced to act dishonestly. These tensions are particularly acute in the UK context given the reliance on just one form of nuclear weapons system for deterrence and the concurrent requirement to pre-delegate secret orders through a ‘letter of last resort’. The consequences for democratic nuclear-armed states are troubling; for public morality, the personal integrity of democratic leaders, and for true democratic accountability. This article concludes that public criticism of political leaders, and citizen voting choices, ought to take account of the problem of transparency posed by policies of nuclear deterrence.

Gianni Vattimo’s Media Philosophy and Its Relevance to Digital Media

1.TECHNOLOGY AND THE QUESTION OF VIOLENCE: APPROACHING VATTIMO'S MEDIA PHILOSOPHYTwo lines of questioning led me to discover and appreciate the work of Gianni Vattimo, and eventually to complete a doctoral dissertation on him. Both these lines have marked the way in which I have read Vattimo, and I will briefly outline them. One set of questions resulted from my interest in the question of disarmament and what was called economic conversion (turning 'swords into ploughshares') in the 1990s. As is known, in the late 1980s the nuclear pile-up on both sides of the iron curtain had created a situation in which it was believed that a full-blown nuclear exchange would lead to total destruction. The only way of securing a cold peace was to maintain a balance of power by ensuring that destruction was mutually assured (Mutually Assured Destruction, MAD). A nuclear weapon, therefore, was a new type of technology: not only a weapon of mass destruction-a category matched by much older military technologies such as the biological agents used in WWI-but a technology without a use. Because nuclear weapons systems were too destructive to be applied in an instrumental, purposeful fashion, destroying through their mere existence any purpose that might be given too them, they represented an incursion of irrationality at the very height of modern scientific achievement. Peter Sloterdijk's Critique of Cynical Reason appeared in 1983, the year the German Bundestag agreed, amidst great controversy, to deploy NATO mid-range cruise missiles on West German territory in order to maintain a state of MAD with the Warsaw pact. Recognizing the challenge this historical situation represented to the western tradition of thought, Sloterdijk's book contained a meditation on the in which he speaks of the atomic bomb as the real Buddha of the west, resting in its silos as the reality and purest possibility1 Sloterdijk referred to an older German writer who developed a powerful philosophical critique of nuclear weapons: Gunther Anders's essays on the nuclear question offered a phenomenological analysis of the Bomb that enquired into the ways in which human existence was challenged by this reality and purest possibility, including the very ways the West has thought about morality and technology. Anders's critique was embedded in a larger philosophy of modern technology published in the two volumes of Die Antiquiertheit des Menschen (The Outdatedness of Human Beings).2 The first of these contained an extensive and philosophical critique of television that turned out to be remarkably prophetic.3 Although a critic of Heidegger in many ways, Anders was among the thinkers who applied Heidegger's philosophy of technology, according to which the essence of technology is nothing technological but lies in a mutual challenging between man and Being that he calls the Gestell (enframing), to our historical experience of technology.While the danger originating in the Gestell was described by Heidegger as the metaphysical forgetting of Being, Anders was driven to draw historical conclusions of this forgetting in the context of the cold war, and in what he called the third industrial revolution that led to human beings' loss of control over the apparatuses they had themselves created.I first read about Vattimo's interpretation of Heidegger's understanding of modern technology as the height of metaphysics in Hans-Martin SchonherrMann's book on the political philosophy of modern technology.4 It was in Vattimo's thinking that the proximity between the metaphysical forgetting of Being, manifest in modern technology, presented me with a method by which to critically interrogate media technologies. Finally, Rafael Capurro, who translated Vatttimo's Fine della modernita into German and is the founder of the International Center for Information Ethics, was key in helping me see the significance of negative hermeneutics in addressing ethical problems of information and communication technologies. …

Trident's Replacement and the Survival of the United Kingdom

A nuclear-weapon system designed to guarantee the UK's survival could hasten its political demise.

Developing probabilistic safety performance margins for unknown and underappreciated risks

Probabilistic safety requirements currently formulated or proposed for space systems, nuclear reactor systems, nuclear weapon systems, and other types of systems that have a low-probability potential for high-consequence accidents depend on showing that the probability of such accidents is below a specified safety threshold or goal. Verification of compliance depends heavily upon synthetic modeling techniques such as PRA. To determine whether or not a system meets its probabilistic requirements, it is necessary to consider whether there are significant risks that are not fully considered in the PRA either because they are not known at the time or because their importance is not fully understood. The ultimate objective is to establish a reasonable margin to account for the difference between known risks and actual risks in attempting to validate compliance with a probabilistic safety threshold or goal. In this paper, we examine data accumulated over the past 60 years primarily from the space program, and secondarily from nuclear reactor experience, aircraft systems, and human reliability experience to formulate guidelines for estimating probabilistic margins to account for risks that are initially unknown or underappreciated. The formulation includes a review of the safety literature to identify the principal causes of such risks.