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Actions Now for the Day After: Findings of the Preventive Defense Day After Project

Firefighters remove a victim from a building reduced to rubble at a mock nuclear detonation drill near Butlerville, Ind., May 10, 2007.
AP Photo

Actions Now for the Day After: Findings of the Preventive Defense Day After Project


April 15, 2008

Author: Ashton B. Carter, Former Co-Director, Preventive Defense Project, Harvard & Stanford Universities

Belfer Center Programs or Projects: Preventive Defense Project


Oral Testimony

Testimony Before The Committee on Homeland Security and Governmental Affairs, United States Senate

Tuesday, April 15, 2008



Ashton B. Carter

Co-Director, Preventive Defense Project

John F. Kennedy School of Government

Harvard University

Chairman Lieberman, Senator Collins, and members of the Committee, thank you for inviting me to testify before you on actions that would be necessary in the 24 hours following a nuclear detonation in an American city - presenting some of the results of what I and my collaborators call The Day After Project.

I applaud you for holding hearings on this terrible prospect, but I regret that you must do so. For while the probability of a nuclear weapon one day going off in a U.S. city cannot be calculated, it is almost surely greater than it was five years ago. North Korea now has the bomb, reflecting the greatest failure of U.S. nonproliferation policy in a generation. Iran could well follow. Pakistan's nuclear technology, already put on the market once by Abdul Qadeer Kahn, could go to terrorists if Pakistan grows unstable. Russia's arsenal remains incompletely secured, some17 years after the end of the Cold War. And enrichment and reprocessing, the essential processes for producing highly enriched uranium and plutonium, respectively, could proliferate with the spread of nuclear power to generate carbon-free electricity.

Meanwhile, in the same five years, terrorism has surged into a global movement. More nuclear materials that can be lost or stolen plus more terrorists aspiring to mass destruction equals a greater probability of nuclear terrorism.

Former Senator Sam Nunn in 2005 framed the need for Washington to do better at changing this math with a provocative question: "On the day after a nuclear weapon goes off in an American city," he asked, "what would we wish we had done to prevent it?"

But in view of the increased risk in recent years, I and my collaborators - former Secretary of Defense William Perry and former Lawrence Livermore National Laboratory Director Michael May - decided we needed to ask a follow-on question to Nunn's: "What should we actually do on the Day After? What steps can our government take now to prepare for that awful contingency?" Accordingly, we convened a workshop in Washington of leading government and non-government experts to consider this question under the auspices of the Harvard-Stanford Preventive Defense Project which Dr. Perry and I co-direct. My testimony summarizes the findings of the workshop, co-authored by May, Perry, and me. The workshop was off-the-record, and none of its participants, listed at the end of my written testimony, is responsible for the report's content. The work was sponsored by the generosity of several foundations and received no government funds. I should also mention that recently I co-chaired, with Ambassador Robert Joseph, a review for the Department of Defense of the programs of the Defense Threat Reduction Agency (DTRA), which would contribute critical technical capabilities to the national effort on the Day After; that report will be available after it passes security review.

Nothing I can tell you from our report would make the Day After anything less than the worst in the history of the Republic. No greater failure of our government's duty to national security could occur than to let this catastrophic event befall our people. Yet it turns out that much could be done to save lives, reduce the cost to the country as a whole, and ensure that our nation, and civilization more broadly, endures. After all, the underlying dynamic would remain a few terrorists acting against the rest of us.

I will summarize our findings in five points.

But first I should make a "zeroth" point: A consideration of the realities of the Day After makes it such that our strongest recommendation to a president who finds himself or herself in this position is: "If I were in your shoes, I wouldn't be in your shoes." Terrorism probably cannot ever be entirely eradicated, since it has so many potential sources in the aberrant motivations of small groups of people or even individuals. But nuclear terrorism can be eradicated. The reason for this is a fortunate blessing of nature: making a nuclear bomb requires highly enriched uranium (HEU) or plutonium, and neither of these metals occurs in nature. They must be man-made. Nature's second gift was to make it comparatively difficult to make either one. Enrichment and reprocessing are beyond the capabilities of even the most sophisticated terrorist group. A terrorist group must obtain HEU or plutonium from the comparatively few governments - you can almost count them with two hands - that have invested the time and treasure to accomplish enrichment or reprocessing. If these governments fully safeguard their materials, there can be no nuclear terrorism. But after that, the laws of nature grow unkind: It is not beyond the ken of a competent terrorist group to make a bomb once it gets the material, especially if it is uranium. It is very difficult to detect these metals in transit, since neither is highly radioactive. And no vaccine can protect against the blast and radiation from a detonation. There is, therefore, no more important national security imperative than to prevent "loose nukes" at the source.

My co-authors and I have long worked on preventing nuclear danger. Perry and May made major contributions to nuclear deterrence and arms control during the Cold War. Perry led efforts to denuclearize Ukraine, Kazakstan, and Belarus while he was Secretary of Defense. I was privileged to run the historic Nunn-Lugar program in the Pentagon as Assistant Secretary of Defense during that period and to participate in these and other successful efforts to secure the Soviet nuclear legacy. Perry and I also participated in the 1994 North Korean nuclear crisis and then I served under him when he was North Korea Policy Coordinator later in the Clinton administration. It was therefore with great regret that we three felt compelled to initiate the Day After Project.

Our five principal findings refer to the detonation of a 10 kiloton weapon at ground level or in a building of a major American city. This is the same yield range as the Hiroshima and Nagasaki weapons and would represent a successful design effort by the perpetrators - North Korea, it appears, did not do as well in its underground test in 2007. The effects would be very different from the World War II bombings, however, since the Hiroshima and Nagasaki bombs were detonated high in the air over Japan and resulted in far less fallout.

1. Our first finding might seem obvious, but it is still not fully reflected in government planning: The scale of this disaster would quickly overwhelm even the most prepared city and state governments. To avoid repeating the Katrina fiasco on a much larger scale, Washington should not pretend that in the instance of nuclear terrorism its role can be defined as supporting state and local responders. And state and local governments - even though their actions to save lives and prevent panic in the first hours would be essential - must abandon the pretense that they could remain "in charge" and in control. The federal government, led by the Department of Homeland Security, should have plans that foresee stepping in quickly, taking full responsibility, and devoting all the resources of the federal government. Related to this finding is that the assets of the Department of Defense will be required in the federal response, including for law enforcement. It was understandable in the early years after 9/11 that DOD showed reticence to involve itself in homeland security response - it had, after all, conflicts in Afghanistan and then Iraq on its hands and feared a raid on the defense budget for homeland security. But that period has passed, and DOD should re-engage on the homeland security front.

2. Our second set of findings has to do with the immediate effects of the detonation. Within a circle about two miles in diameter - the length of the Mall here in Washington - the devastation from the blast would be near total. Then just downwind of that circle, in a cigar-shaped area a few miles long, the fallout would be severe enough to submit people who lived there to lethal doses of radiation even if they took modest shelter (for example, in a basement). If these people knew who they were (on a clear day they could just look in the sky and see the dust cloud coming their way, somewhat akin to the long plume of yellow dust from the Twin Towers wafting towards New Jersey on 9/11), they would have to evacuate quickly to avoid lethal exposure. Elsewhere in the city, where most of the inhabitants would in fact be working or sleeping, people would have more choices that emergency planners would need to manage. People upwind would not need to take any action. Downwind, but outside of the "hot" cigar, the best move for many people would be not to move at all, but to seek moderate shelter (somewhere where either mass shields them or distance attenuates the radiation reaching them). The worst thing for people to do in much of the downwind area would be to take to the highways at the same time, allowing the dust to settle on them when they were unsheltered and stuck in traffic. The radiation dose rate would drop off roughly in inverse proportion to the passage of time, so that after three days one could take three times as long to evacuate. Sheltering for this period of time would not be difficult and should not be compared to the Dr. Strangelove mineshaft-type civil defense fallout shelters of the 1950s. Managing the optimal mix of evacuation and sheltering would be the responsibility of the government, which would need to be able to quickly predict the path of the plume, advise citizens, close some roads, and so on.

3. Our third set of findings deals with the long-term effects of the detonation, which are dominated by the problem of radiation. Radiation is unique to nuclear terrorism and uniquely frightening to most people. People far enough downwind that the radiation did not present an immediate danger could leave their homes or stay, leave for a while and come back, come back briefly to recover a pet or valuables, or never live in the area again. Their choices would be determined by the dose of radiation they would be willing to absorb. The doses far downwind would not make people die or even get sick. Instead, these "low" doses would only raise their statistical chance of getting cancer later in life and dying from it - raising it from 20 percent, which is the chance we all have on average - to something higher: 21 percent, 22 percent, up to 30 percent at the maximum survivable exposure. For the great majority of people downwind, the chance would be small enough (20.1 percent, let's say), that they would not notice it themselves but the public health authorities would notice, years later, a greater cancer death rate in this population.

A critical matter related to low- and moderate-dose exposure has to do with the choices for first responders and troops sent to the stricken city. Few would choose to have their chance of dying of cancer rise from 20 percent to 30 percent. But in the case of small probabilities - 20.1 percent, for example, a first responder might be willing to go into the radiation zone for a short time. Protocols already exist that provide for higher permitted doses for workers in nuclear industries than for the public at large. These choices can ultimately only be made by individuals, but the protocols they follow must give them the best chance to know which areas are hotter than others and how long they can stay in the zone to accomplish their duties. Once a first responder had absorbed the permitted dose, he or she could no longer serve in the zone. All this obviously has huge implications for the competence of the response, for how it is planned, and for how many personnel must be rotated in and out of the zone.

4. Our fourth finding is perhaps the most important of all. It is the unpleasant fact that the first detonation probably won't be the last...or at least it won't feel that way. Let me explain. If terrorists manage to find enough material for a bomb, or to steal or buy a bomb, who's to say they didn't get two, or three, or four from the same source? There is no technical or operational reason why nuclear terrorism should come one-at-a-time. What is absolutely clear is that terrorists will claim to have more after they detonate the first one - after all, their intent is to sow terror. Public officials will therefore have to behave as though there are more. The public surely will. Said differently, nuclear terrorism will not seem like an incident, but instead like a syndrome or campaign of terror. So people in other cities than the one struck will want to evacuate or at least move their children out of the cities, as the British did in World War II.

To prevent a second, third, and fourth detonation, the U.S. government - by now itself relocated out of Washington - will be desperately trying to find the terrorists and trace the source of the bombs. We know that the investigation must and surely will (aided by radiochemical forensics2) ultimately lead to a government somewhere - Pakistan, North Korea, Russia, or any one of a dozen or so governments that operate hundreds of facilities where bombs or fissile material are stored - since the terrorists surely did not make the HEU or plutonium but instead stole, bought, or otherwise obtained it from a government facility. It has become something of a fad to say that the U.S. will retaliate against any government found to be the source of a bomb detonated on the U.S. And of course that would be a reasonable thing to consider if the government involved was in any way witting in the plot. But on the Day After, our national interest will take us in another direction - one of cooperation, not threats - since we will desperately need the help of those governments to track down the remaining bombs and put the campaign of nuclear terrorism to an end.

5. Our fifth and last set of findings has to do with the effects of the outbreak of nuclear terrorism on our society and government. I believe that the U.S. government itself, in a form recognizable to the citizenry as constitutional, would survive even if the first bomb struck Washington. On my first job in the Pentagon working for Caspar Weinberger, I had some involvement with the continuity of government effort to deal with the far more daunting task of "surviving the national command authority" under a rain of 3000 equivalent megatons of Soviet missile warheads. Then again in the Clinton administration after the Cold War ended, I saw this effort adapted to contingencies like nuclear terrorism. I am not current on these efforts, but I would be very surprised - especially after 9/11 - if they were not robust and well thought-out.

A bigger issue is survival of governance itself - of the people's sense of well-being and safety...that their institutions were competent to respond to the emergency and protect them...that important things had been thought through in advance...that they were given good advice about how to act on the Day After...ultimately, that they could raise their children in big urban settlements. This is another reason, besides saving lives and property on the Day After, for us to think now about our response. It is also important that we anticipate now our natural impulse on the Day After to over-react. We should resolve now that any extraordinary measures taken on the Day After have a sunset clause, and that they undergo a total review periodically to see if they continue to strike the right balance between responding to nuclear terrorism and other objectives that constitute the good life in civil society.

This is also an appropriate note on which to close. The more competent and capable our government is on the Day After, and the more quickly and surely it can bring the campaign of nuclear terror to an end and make sure its recurrence is much less likely than it is now, and the less it is prone to panic and over-reaction, the less this awful event needs to lead to a change in our way of life. That is why it is important for the Congress and this Committee to address the Day After.

Thank you for inviting me to be with you.

Full text of the April 2007 workshop report is available here.

Full text of Dr. Carter's testimony is also available through the attached document and the link below.


Full text of this publication is available at:

For Academic Citation:

Carter, Ashton B. "Actions Now for the Day After: Findings of the Preventive Defense Day After Project." Testimony to . April 15, 2008.

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Preventive Defense Project

The Preventive Defense Project (PDP) is a Harvard-Stanford research collaboration, co-directed by Ashton B. Carter and William J. Perry.

Ashton B. Carter

In February 2015, Ashton B. Carter became Secretary of Defense for the United States.

Dr. Carter is former director of the Belfer Center's Preventive Defense Project and former director of what is now the Belfer Center. He is on leave.


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