The death of Osama bin Laden eliminated the terrorist who most analysts believe was the most committed to -- and capable of -- obtaining and using a nuclear weapon.
But there is only one way to truly eliminate the threat of nuclear terrorism. America must be just as relentless in achieving President Obama's goal of eliminating nuclear weapons from the planet as we were in pursuing bin Laden.
Many "hardnosed" politicians and analysts consider the ideal of eliminating all nuclear weapons from the world to be "naive" or "utopian."
I recently returned from a seminar on nuclear policy in Vienna, Austria where presenters included some of the leading experts on the spread of nuclear weapons, nuclear power, nuclear disarmament and nuclear terrorism. I came away convinced that the term "naïve" could only be used to describe those who believe that we can continue to live in a world still bristling with nuclear weapons without endangering our very existence.
Last fall the Senate approved the New START arms control agreement with Russia that reduced each side's strategic nuclear arsenal to 1,550 nuclear war heads. That treaty represented a major step forward - following on the original START Treaty negotiated between President Ronald Reagan and Soviet Prime Minster Mikhail Gorbechev. But this agreement is only a down payment on the far more fundamental goal of completely ridding the world of all nuclear weapons.
Why is that goal so critical to our long-term survival?
All told there are 25,000 nuclear weapons currently in existence. Ninety percent of these are controlled by the United States and Russia. They include the strategic nuclear weapons that are now subject to the New START agreement, as well as thousands of tactical nuclear weapons that are intended to be used on the battlefield - and many non-deployed nuclear weapons that remain in storage and are not currently targeted at the bases and cities of an adversary.
The remainder are in the hands of the seven additional nuclear nations: China, Britain, France, Israel, India, Pakistan and North Korea. Currently China, Britain and France have hundreds of war heads each. Israel has 80 warheads. And North Korea has ten.
Notwithstanding the end of the Cold War almost twenty years ago, thousands of war heads remained on alert - targeted at bases and cities in Russia and the United States. From the time a radar-computer system gives one of the two sides warning of an impending attack, the other side has just minutes to decide if it should launch a counter attack or risk defeat and obliteration.
But that is far from the worst of it. Nuclear technology is now 65 years old. The skill and know-how to create a nuclear weapon is widespread. Increasing numbers of nations have sought to enter the nuclear club - most recently North Korea and potentially Iran.
An increasingly unstable regime in Pakistan controls a growing nuclear arsenal.
Worse, al Queda and other terrorist organizations have vowed to obtain and actually use nuclear weapons.
The status quo - the balance of terror - that for six decades prevented a nuclear war between the U.S. and Russia is every day being made more unstable by the increasing numbers of nuclear players - and by the potential entry of non-state actors. Far from being deterred by the chaos and human suffering that would ensue from nuclear war - actors like al Queda actively seek precisely that kind of cataclysm.
The more nuclear weapons that exist in the world - and more importantly the more weapons-grade fissile material that can be obtained to build a nuclear weapon - the more likely it is that one, or many more, will actually be used.
In the 1980's the specter of a "Nuclear Winter" helped spur the movement for nuclear arms reduction between the U.S. and Soviet Union. Studies showed that smoke caused by fires set off by nuclear explosions in cities and industrial sites would rise to the stratosphere and envelope the world.
The ash would absorb energy from the sun so that the earth's surface would get cold, dry and dark. Plants would die. Much of our food supply would disappear. Much of the world's surface would reach winter temperatures in the summer.
A recent study published in Scientific American by scientists Alan Robock and Owen Brian Toon -- using modern climatic computer models -- found that even a regional nuclear conflict between India and Pakistan would shroud the entire planet in a cloud of dust for 10 years and would massively diminish world food supply.
The fine dust particles from nuclear fires would rise into the stratosphere where there is no rain to clean the air. As a consequence it would take years to gradually settle to the earth's surface.
Their study assumed that India and Pakistan would each use 50 nuclear weapons. The total of 100 weapons used represents only .4% of the world's 25,000 nuclear weapons. It found that such a war would kill approximately 20 million people from the direct bomb effects and subsequent fires and radiation. Their model shows it would likely kill another 1 billion people - about a seventh of the world's population - from starvation caused by the agricultural collapse.
These effects would happen over a decade. You can imagine that those threatened with starvation would not die quietly. Rather the world would witness an economic and political crisis without any parallel in recorded history.
Robock and Toon tested their model against the actual the effects of volcanic eruptions such as those of Tambora in 1815, Krakatau in 1883 and Pinatubo in 1981. They found that their model replicated observed results. For instance, after the eruption of Pinatubo, sulfate aerosol clouds were carried around the world by winds. As a result global temperatures dropped by an average of .25 degrees Centigrade. In addition, global precipitation, river flow and soil moisture all decreased.
Mt. Tambora's eruption in Indonesia in 1815 was the worst volcanic eruption in 500 years. Dust from the eruption blocked the sun and caused global temperatures to drop by .5 Degrees Centigrade. 1816 was known as the "year without summer." In New England - thousands of miles from Indonesia - even though the average summer temperature dropped only a few degrees, crop-killing frosts happened in every summer month. After each frost, farmers replanted only to see their crops killed the next month.
They also tested their model against the actual firestorms created by the nuclear attacks on Nagasaki and Hiroshima, the fire bombing of Dresden, and the fires caused by the 1906 San Francisco earthquake. Each actual episode confirmed their result.
Finally, Robock and Toon point to archeological evidence that the collision of an asteroid with Yucatan 65 million years ago created a similar dust cloud that shrouded the earth and caused the extinction of the dinosaurs.
The Robock-Toon model found that smoke from the imaginary India-Pakistan regional nuclear war would cover every continent within two weeks and would continue to have massive impacts on the global climate for ten years.
The use of nuclear weapons in any part of the world would affect every living creature. Their use is simply unthinkable. Yet the United States and Russia maintain thousands on hair trigger alert. And terrorists who affirmatively desire to cause global Armageddon actively seek their use.
If someone looked back on our generation from the vantage point of a hundred years in the future, they would have a hard time imagining what we were thinking if we allowed the continued existence of weapons that we could never use without endangering our very existence.
That is precisely why a quartet of retired Cold Warriors: former Republican Secretaries of State Henry Kissinger and George Schultz, former Defense Secretary William Perry and former Georgia Senator Sam Nunn - have combined to sponsor a campaign to eliminate all nuclear weapons.
That's also why President Obama has renewed Ronald Reagan's often-forgotten call for a nuclear weapon free world.
Eliminating nuclear weapons will not be easy - and it must be done in a series of steps over a number of years. But there should be no doubt whatsoever that it must be humanity's goal.
Immediate steps include U.S. Senate ratification of the nuclear test ban treaty that would ban all future nuclear tests. The United States signed this treaty years ago, but it has yet to be approved by the Senate. As a practical matter, final U.S. approval is necessary in order to put this treaty into effect. In the short term, given the United State's enormous advantage in nuclear test data, this treaty would freeze in place a U.S. nuclear advantage. Yet it has been opposed by Neocons who want one day to create a new generation of nuclear weapons that they believe may need to be tested.
Our government should also begin a new round of arms reduction talks with the Russians. As a practical matter, non-nuclear states are simply unwilling to accept the view that they should forego the possession of nuclear weapons if the United States and Russia - which control 90% of all the nuclear weapons on the planet - do not meet their obligations under the Nuclear Non-proliferation Treaty to continuously reduce their stockpiles.
One of the central components of a strategy to achieve a nuclear weapon free world must be the negotiation of a new international treaty to control and prevent the new production of weapons-grade fissile materials. The know-how to create nuclear weapons will never disappear. But fissile materials - highly enriched uranium or plutonium - that can be used to create these weapons - can be controlled. Nuclear reactors used for peaceful purposes do not necessarily require weapons grade fissile material. Neither of these elements occurs in nature in a form usable to build nuclear weapons. Both must be created by human manufacturing processes that can be monitored and prevented with appropriate international agreements. Current weapons-grade fissile materials could be locked down under international control, and further production could be banned.
The elimination of nuclear weapons is certainly one of the most important issues on the human agenda.
A few years ago a planetary scientist named David Grinspoon wrote a book called, Lonely Planets. It explores the question of extraterrestrial life.
Toward the end of his book, Grinspoon speculates on the chances of survival for intelligent life in the universe. He argues that every civilization of intelligent creatures must pass through a gauntlet that tests whether the values and political structures of the society are capable of keeping pace with the exponentially increasing power of the society's technology. If its values and political structures can keep pace with technological change, the society may pass into a phase of enormous freedom and possibility. If it does not, the power of its own technology will destroy it. Perhaps, he postulates, civilizations are like seahorses. Many are born, but only a few survive.
For the first time, sixty-five years ago, human society entered that gauntlet. Our technological growth reached a point of takeoff that for the first time gave us the power to destroy ourselves and all life on our tiny, fragile planet. From that moment on, the race was on.
The next several generations of humans will decide how that race turns out. We won't simply observe it, or describe it; we will decide it. Whatever the future holds will be a result of human decision for which we are all responsible.
We will decide if we pass through that gauntlet or - like our cousins the Neanderthals - become evolutionary dead ends. We will decide if humanity passes into a new era of possibility and freedom - or the human story simply ends.
Robert Creamer is a long-time political organizer and strategist, and author of the book: Stand Up Straight: How Progressives Can Win, available on Follow him on Twitter @rbcreamer.