Nuclear Age Peace Foundation

Tag: Nuclear Risk

  • What Factors Make Nuclear War More Likely?

    This article was originally published by The Hill.

    We know that the risk of nuclear war is not zero. Humans are not capable of creating foolproof systems. Nuclear weapons systems are particularly problematic since the possession of nuclear weapons carries an implicit threat of use under certain circumstances. In accord with nuclear deterrence theory, a country threatens to use nuclear weapons, believing that it will prevent the use of nuclear weapons against it.

    Nearly 15,000 nuclear weapons are currently under the control of nine countries. Each has a complex system of command and control with many possibilities for error, accident or intentional use.

    Error could be the result of human or technological factors, or some combination of human and technological interaction. During the more than seven decades of the Nuclear Age, there have been many accidents and close calls that could have resulted in nuclear disaster. The world narrowly escaped a nuclear war between the United States and Soviet Union during the 1962 Cuban Missile Crisis.

    Human factors include miscommunications, misinterpretations and psychological issues. Some leaders believe that threatening behavior makes nuclear deterrence more effective, but it could also result in a preventive first-strike launch by the side being threatened. Psychological pathologies among those in control of nuclear weapons could also play a role. Hubris, or extreme arrogance, is another factor of concern.

    Technological factors include computer errors that wrongfully show a country is under nuclear attack. Such false warnings have occurred on numerous occasions but, fortunately, human interactions (often against policy and/or orders) have so far kept a false warning from resulting in a mistaken “retaliatory” attack. In times of severe tensions, a technological error could compound the risks, and human actors might decide to initiate a first strike.

    There are many other factors that affect the risk of nuclear war. These include an increase in the number of countries possessing nuclear weapons and a greater number of nuclear weapons in each country’s nuclear arsenal. Both of these factors increase complexity and make the risk greater. Additionally, the higher the alert status of a country’s nuclear arsenal, the shorter the decision time to launch and the greater the risk of nuclear war. The risks are compounded when tension levels increase between nuclear-armed countries, increasing the likelihood of false assumptions and precipitous action.

    Nuclear policies of the nuclear-armed countries can also raise the risk level of nuclear war. Policies of first use of nuclear weapons may make an opponent more likely to initiate a first strike and thus make a nuclear war more likely. First use is generally a default policy, if a country does not specifically pledge a policy of no first use, as have China and India. Policies of launch-on-warning cut into decision time for leaders to decide whether or not to launch a “retaliatory” strike to what may be a false warning The deployment of land-based missiles also raises the risk level due to the “use them or lose them” nature of these stationary targets.

    In addition to identifiable risks of nuclear war, there are also unknown risks — those that cannot be identified in advance. Unknown risks include little-understood possibilities for cyber-attacks on nuclear weapons systems, attacks that could potentially either activate or deactivate nuclear-armed missile launches.

    Given the catastrophic consequences of nuclear war, including destruction of civilization and human extinction, identifying and eliminating the factors making nuclear war likely or even possible is imperative. There are simply too many possibilities for failure in such a complex system of interactions.

    This leads to the conclusion that the risks are untenable, and all nations should move rapidly to negotiate the elimination of all nuclear arms. While doing so, nations would be well served to adopt and declare policies of no first use and no launch-on-warning, and to eliminate vulnerable land-based missiles from their arsenals.

  • What Are Acceptable Nuclear Risks?

    martin_hellman1This article was originally published on Defusing the Nuclear Threat.

    When I read Eric Schlosser’s acclaimed 2013 book, Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety, I found a tantalizing revelation on pages 170-171, when it asked, “What was the ‘acceptable’ probability of an accidental nuclear explosion?” and then proceeded to describe a 1957 Sandia Report, “Acceptable Premature Probabilities for Nuclear Weapons,” which dealt with that question.

    Unable to find the report online, I contacted Schlosser, who was kind enough to share it with me. (We owe him a debt of gratitude for obtaining it through a laborious Freedom of Information Act request.) The full report, Schlosser’s FOIA request, and my analysis of the report are now freely accessible on my Stanford web site. (The 1955 Army report, “Acceptable Military Risks from Accidental Detonation of Atomic Weapons,” on which this 1957 Sandia report builds, appears not to be available. If anyone knows of an existing copy, please post a comment.)

    Using the same criterion as this report*, which, of course, is open to question, my analysis shows that nuclear terrorism would have to have a risk of at most 0.5% per year to be considered “acceptable.” In contrast, existing estimates are roughly 20 times higher.**

    My analysis also shows, that using the report’s criterion*, the risk of a full-scale nuclear war would have to be on the order of 0.0005% per year, corresponding to a “time horizon” of 200,000 years. In contrast, my preliminary risk analysis of nuclear deterrence indicates that risk to be at least a factor 100 and possibly a factor of 1,000 times higher. Similarly, when I ask people how long they think we can go before nuclear deterrence fails and we destroy ourselves (assuming nothing changes, which hopefully it will), almost all people see 10 years as too short and 1,000 years as too long, leaving 100 years as the only “order of magnitude” estimate left, an estimate which is 2,000 times riskier than the report’s criterion would allow.

    In short, the risks of catastrophes involving nuclear weapons currently appear to be far above any acceptable level. Isn’t it time we started paying more attention to those risks, and taking steps to reduce them?

    *The report required that the expected number of deaths due to an accidental nuclear detonation should be no greater than the number of American deaths each year due to natural disasters, such as hurricanes, floods, and earthquakes.

    ** In the Nuclear Tipping Point video documentary Henry Kissinger says, “if nothing fundamental changes, then I would expect the use of nuclear weapons in some 10 year period is very possible” – equivalent to a risk of approximately 10% per year. Similarly, noted national security expert Dr. Richard Garwin testified to Congress that he estimate the risk to be in the range of 10-20 percent per year. A survey of national security experts by Senator Richard Lugar was also in the 10% per year range.