(Photo: Stephen Train / Flickr)I offer a few reflections in an effort to separate fact from fiction with regard to nuclear weapons, their capacity for devastation and our ability to assure global security by preventing their use.

First, today’s nuclear arsenals are capable of omnicide, the death of all. In that sense, nuclear weapons are not really weapons but instruments of annihilation. They place all complex life at risk of extinction.

Omnicide is possible because of the unique capacity of nuclear weapons to cause a “nuclear winter” and to trigger “nuclear famine.” In addition to the ordinary ways that nuclear weapons destroy – blast, fire and radiation – they have the capacity to block sunlight from reaching the earth, shorten growing seasons, and lead to the destruction of crops, resulting in global nuclear famine.

Second, nuclear weapons are justified by their possessors by their belief in the effectiveness of nuclear deterrence.

We must always keep in mind that nuclear deterrence is not a fact; it is a hypothesis about human behavior. It is a hypothesis that posits rational leaders; and it is, in fact, highly irrational to believe that humans will behave rationally at all times under all conditions. How many national leaders are you aware of who always act rationally, regardless of the circumstances?

It is also true that humans are fallible and prone to error, even when they construct elaborate safeguards. Examples of human fallibility are found in the nuclear power plant accidents at Three Mile Island, Chernobyl and Fukushima, and in numerous accidents with nuclear weapons in transport, such as the refueling accident over Palomares, Spain.

As Ban Ki-moon said earlier this year in a speech at the Monterey Institute of International Studies: “Nuclear deterrence is not a solution to international peace and stability. It is an obstacle.”

Third, I urge you to remember the Maginot Line. It was a high-tech wall that French leaders believed would prevent another invasion of their country, as had occurred in World War I. The Maginot Line was highly regarded right up to the time that it failed, catastrophically for France, when the German attackers simply marched around it.

I view nuclear deterrence theory as a Maginot Line in the mind. It is likely to be relied upon right up until the moment it fails, and when it fails it will be catastrophic, far more so than in the French case. Like the original Maginot Line, it will seem clear after the fact that it was destined to fail.

What is missing from the discourse on nuclear armaments among national leaders is political will for nuclear weapons abolition, a sense of urgency and the courage to lead. Mr. Obama spoke in his 2013 State of the Union Address about the US “leading the global effort to secure nuclear materials that could fall into the wrong hands.” The problem with the president’s perspective is that all hands are the wrong hands.

Who will make this clear to Mr. Obama and to the leaders of the other nuclear weapons states? This is a role for the citizens of the nuclear weapon states and for the leaders of middle-power countries. It is necessary if we are to preserve our world and pass it on intact to new generations.

Mr. Obama also said that “our ability to influence others depends on our willingness to lead.” Who will step up and lead on this mostcritical of all issues for humanity’s future?

Strategies for nuclear weapons, based on nuclear deterrence, have been MAD (Mutually Assured Destruction). MAD has given way to SAD (Self-Assured Destruction), as today’s arsenals of thermonuclear weapons have the capacity to trigger Ice Age conditions (leading to nuclear famine) that would assure the destruction of the attacking nation, even without retaliation.

We must have the courage to move past MAD and SAD to PASS (Planetary Assured Security and Survival). This will require moving rapidly but surely to the total abolition of nuclear weapons, as required by the Non-Proliferation Treaty.

I urge national leaders and security specialists, as well as the public, to base their strategic thinking, leadership and action regarding nuclear weapons on three basic understandings that separate fact from fiction, truth from hypothesis. First, nuclear weapons are capable of omnicide. Second, nuclear deterrence is only a hypothesis about human behavior, not a fact that can be relied upon for the indefinite future. Third, the Maginot Line was fancy and high-tech and was thought to be foolproof by most security experts, but it failed to provide a defense when it mattered, and its failure was devastating for France.

Nuclear deterrence is a Maginot Line in the mind, and its failure would be devastating, not only to nuclear armed countries, but to people everywhere, as well as to the future of complex life on the planet.