Reframing the Nuclear Threat

What nuclear threats do we face today? America went to war because its leadership believed Iraq had nuclear and other weapons of mass destruction. We are reminded daily of the potential dangers of Iran turning its quest for nuclear energy into a weapons capability. We are locked in a deep struggle to get North Korea to give up its nuclear status demonstrated in last fall’s test. Concerns about Russia’s nuclear arsenal are resurfacing. And, we are constantly reminded that we must wage America’s “war on terror” to avoid the nexus of international terrorism and nuclear weapons.

All nuclear threats are not alike. How do these and other nuclear threats compare in terms of severity or likelihood? And how can we effectively address them? It is useful to think of today’s nuclear threats at three levels. First is an all-out exchange of nuclear warheads—hundreds of them—that would destroy civilization as we know it. Next is a limited, but still disastrous exchange—tens of warheads —that would create levels of destruction not seen since World War II. The third level is the use of one or several nuclear bombs, which would threaten our way of life. Reframing the nuclear threat in this way allows us to gauge our level of concern and formulate meaningful preventive strategies.

An all-out nuclear exchange could occur today only between the United States and Russia, which still maintain many thousands of warheads in their nuclear inventories. A nuclear war between these two countries represents the only existential threat to the United States.

The end of the Cold War rendered this threat highly improbable but not impossible. An accidental or unauthorized launch followed by a response is still possible. To eliminate this threat, the United States and Russia should follow through on detargeting and commit to de-alerting their nuclear forces—to remove them from high alert status that allows a launch within minutes to pre-identified targets.

The two nations should commit to making major reductions in their nuclear stockpiles and eventually eliminating them. In the midst of the Cold War, President Ronald Reagan and Soviet General Secretary Mikhail Gorbachev reduced their stockpiles and even came close to an agreement to lead the world in abolishing nuclear weapons. Last January in a Wall Street Journal op-ed, George Shultz, William J. Perry, Henry Kissinger, and Sam Nunn called for a renewal of that vision by outlining steps to be taken now.

To move more rapidly toward much smaller numbers, I would add that leaders in both nations should undertake a zero-base nuclear assessment that would answer this question: If you were creating a stockpile from scratch today, how many weapons would you need to meet the current threat? Such a calculus would yield much lower numbers than trying to decide how many weapons you can live without. U.S. and Russian nuclear postures toward China should also carefully avoid provoking a Chinese nuclear buildup.

An exchange of tens of nuclear warheads is somewhat less improbable than nuclear war between Russia and the United States. But at this level, potential confrontations include nuclear exchanges between India and Pakistan, or between the United States and China—over Taiwan, for example, or on Russia’s southern border, or in the Middle East, between Israel and possibly Iran in the future. To limit the possibilities, it is crucial to stop more countries from acquiring nuclear weapons. The fewer fingers on the nuclear trigger, the better.

The United States should play a leading role in reinforcing the nuclear nonproliferation regime, centered on the 37-year-old Non-Proliferation Treaty (NPT), which allows a country to come within a whisker of building a bomb. A global expansion of nuclear power will pose additional challenges to the system. We need new rules of engagement for expanding nuclear power, including viable international controls on uranium enrichment and plutonium reprocessing.

To encourage non-nuclear weapon states to keep their end of the NPT bargain and refrain from acquiring the bomb, the five nuclear weapon states must show a greater commitment to working in good faith toward eventual elimination of their arsenals, as pledged under Article VI of the treaty.

Security guarantees from the United States and other nuclear weapon states can help curb some countries’ nuclear ambitions by alleviating fears of invasion by major world powers or by regional foes. India and Pakistan—two nuclear weapon states that aren’t parties to the NPT—should continue to pursue confidence-building measures to avoid miscalculation and potential nuclear war. We should help realize the nuclear-free zones that states are calling for in the Middle East, on the Korean peninsula, in Central Asia and in as many other regions as possible.

The United States and other states with nuclear weapons can also lower the risk of limited war by declaring a no-first-use policy, reserving nuclear weapons only as weapons of last resort.

The use of one or several nuclear bombs today is more likely than it was during the Cold War. If detonated in a big city, the damage would be catastrophic. Humankind would survive such a catastrophe, but it could gravely threaten our way of life. A country or a terrorist group in possession of a rudimentary nuclear bomb could deliver such a weapon in a van, boat, or plane. North Korea could do so, in desperation; Israel could do so in response to an existential threat; and under current doctrine, the United States or Russia could do so in response to a chemical, biological, or radiological attack. More likely, and hence of greater concern, is that terrorists would use a nuclear bomb, if they could get one.

The most likely route for terrorists to acquire a bomb is to devise one from stolen or diverted fissile materials. Theft or diversion of a ready-made weapon is far less likely.Building a rudimentary bomb is not easy but is judged to be within the capabilities of some sophisticated terrorist groups if they are able to obtain fissile materials.

Although it is widely recognized that keeping bomb materials out of terrorists’ hands is essential, the difficulty of doing so, especially from a technical standpoint, is not well understood. Only a few tens of kilograms of plutonium or highly enriched uranium are required for a bomb, yet almost 2 million kilograms of each exist in the world today, and some of it is not adequately secured. Securing these materials requires greater commitment to nuclear materials safeguards by all countries that possess them. It calls for greater urgency to protect and eventually eliminate highly enriched uranium in research reactors and facilities around the world. Bilateral or multilateral sting operations to intercept nuclear black market trade may help locate material already outside of state control. International cooperation in building databases and detection systems will improve nuclear forensics and attribution.

Each level of nuclear threat implies a different strategy of prevention. But three common aspects emerge as priorities for national and international policymaking:

• The fewer nuclear weapons, the better.
• The fewer fingers on a nuclear trigger, the better.
• Keeping fissile materials out of terrorists’ hands is essential.

Finally, this is not a problem for the United States alone to solve. It can only be solved through international cooperation.