America At War:
Weapons of Mass Destruction
With Jim Walsh
Kennedy School of Government Fellow
Wednesday, Dec. 5, 2001; 1 p.m. EST

U.S. intelligence agencies have recently concluded that Osama bin Laden and his al Qaeda terrorist network may have made greater strides than previously thought toward obtaining plans or materials to make a crude radiological weapon that would use conventional explosives to spread radioactivity over a wide area, according to U.S. and foreign sources.

Jim Walsh, Belfer Center for Science and International Affairs Fellow at the John F. Kennedy School of Government at Harvard, was online to discuss terrorism and weapons of mass destruction.

A transcript follows.

Editor's Note: Washingtonpost.com moderators retain editorial control over Live Online discussions and choose the most relevant questions for guests and hosts; guests and hosts can decline to answer questions.

Alexandria, Va.: What is the likelihood that bin Laden has weapons of mass destruction at his disposal?

Jim Walsh: It is likely that bin Laden has some weapons of mass destruction. In particular he probably has low grade forms of chemical weapons, he may or may not have biological agents, it is highly unlikely he has nuclear weapons, but he may have materials to construct a dirty or radiological bomb. These conclusions are based on court testimony, bin Laden's own statements and intelligence reports.

Philadelphia, Pa.: I'm unclear on how big a blow a "dirty nuke" would be: I've seen it described some places as more frightening than damaging and in at least one other source as something like Chernobyl. This is quite a range: if one is used in downtown D.C., what happens? People who happen to be outdoors at the time are at increased risk of disease later in life; all of D.C. and Arlington need to be abandoned for decades to come; or something in between?
And, maybe this is a question impossible to answer, but what's the risk? If you read the two top stories in Tuesday's Post together, you could conclude the authorities are worried about this happening in D.C. any day now. Can you (I hope!) ease our minds?
Thank you.

Jim Walsh: Excellent question.

Reporting of catastrophic consequences is overdrawn. A recent study conducted by a national panel of radiation experts concluded that the effects would be limited. Most of those killed by a dirty bomb will be people who die because of the conventional explosion, not the nuclear materials. How lethal the bomb is depends on three factors: the amount of conventional explosives, the quantity of nuclear material and the character of he nuclear material. Some nuclear materials are highly radioactive, others aren't, some materials last tens of thousands of years, others dissipate in seconds. It is unlikely that terrorists would be able to obtain the most radioactive nuclear materials. There would be risk of cancer or other related illness to exposure of radioactive material but most people would not be exposed for a long period and so the real concern is fear and panic rather than a large death toll.

Falls Church, Va.: Have there been any incidents, that we are aware of, of a "dirty" bomb being used against any populations anywhere in the world? Iraq? Russia? Thanks.

Jim Walsh: Another good question.

To date there has been no successful use of a radiological weapon by either a country or a terrorist group. Radiological weapons have been around since the dawn of the nuclear age. Most countries that considered nuclear weapons also considered radiological weapons but concluded that they were not effective as military weapons. There are two recent reports regarding radiological weapons -- one is that Chechan rebels left a can of cesium in a Moscow park as a warning. There have also been reports in the Russian press of a radiological booby trap that had been disarmed. These reports remain unconfirmed.

In sum, we have no direct experience of a successful use of a radiological weapon.

Washington, D.C.: How far would the effects of a "dirty bomb" spread? If set off in a downtown area, would it contaminate only several blocks, or the entire city? Thanks.

Jim Walsh: The answer is in most cases city blocks not an entire city, but it depends on the size and character of the nuclear material. Exploding a dirty bomb downtown where there are tall buildings mean that those buildings will constrain the effects of the blast.

New York, N.Y.: Isn't it very simple to contaminate the water supply with radiological materials? One vial of plutonium in the water supply could kill thousands?

Jim Walsh: Actually it is quite difficult to poison a water supply because of the volume of water in a typical reservoir. Officials meeting just this week have reaffirmed the basic safety of the nation's water supply.

Plutonium is one of the most highly radioactive nuclear materials and it is more likely to kill a terrorist before completing their mission as it is likely to contaminate innocent victims.

Washington, D.C.: Does the US government, particularly the Boarder Patrol or Customs Service, employ the use of radiation monitors at border crossings or points of entry to the U.S.? If so, have there been any studies done of their effectiveness (like in airline baggage screening)? If not, why?

Jim Walsh: The use of radiation monitoring equipment is not yet widespread, but it is becoming more so - not only in the U.S. but other countries as well. IAEA, or the International Atomic Energy Agency, has begun working with countries to improve their ability to detect smuggled nuclear materials, but there is a lot left to be done.

New York, N.Y.: What type of delivery vehicles are viable? How does this limit the weapons effectiveness?

Jim Walsh: People most often talk about truck bombs and suitcase bombs. A suitcase bomb with traditional conventional explosives would be so small as to limit the effectiveness of the weapon. The primary concern therefore is the larger scale truck bomb.

Jim Walsh: So there is a trade off here for terrorists. Smaller weapons may be easier to smuggle, but they will have less of an impact.

Falls Church, Va.: Regarding dirty bombs "Some nuclear materials are highly radioactive, other's aren't, some materials last tens of thousands of years, others dissipate in seconds."

Does that mean that it is quite possible for a certain section of the city to be off-limits to habitation for years and years? What kind of clean-up is possible after a dirty bomb to minimize the level of radioactivity in the area such that it will be safe to humans?

Jim Walsh: The most common nuclear materials, and thus those most likely to be stolen and used in a radiological bomb, tend to be the materials that are less radioactive and have a shorter half-life. It might however take years to fully clean a bomb site. It is worth noting that the World Trade Center site itself will likely take more than a year of clean up.

Washington, D.C.: Dear Mr. Walsh,
Media reports on this issue have given somewhat varied information, but it is my understanding that the Bush Administration REDUCED funds the U.S. has been providing to shore up weak Russian nuclear security. Is this the case to your knowledge? How could this possibly be justified? Is this really the appropriate place to save a few (million) dollars? As the head of the International Atomic Energy Commission said, (nuclear) security is as good as its weakest link -- the fact that we have helped secure SOME Russian and post-Soviet facilities means virtually nothing if some are still inadequately supervised!
Thanks for your comment.

Jim Walsh: I absolutely agree with the questioner's comments. In the last Bush energy Bush budget the president recommended spending fewer dollars than we did last year helping Russia protect its vulnerable nuclear materials. At the Crawford Summit in Texas President Bush endorsed the idea of expanding nuclear cooperation with Russia, but to date the dollars have not matched the rhetoric and the recent supplemental budget intended to pay the cost of fighting terrorist there was not a single dollar for nuclear materials protection or non proliferation. This record is at odds with the recommendations of a bipartisan commission headed by former Senate Majority Leader Howard Baker (President Bush's current Ambassador to Japan) that we triple funding for these programs.

Mt. Lebanon, Pa.: The U.S., and others, have weapons of mass destruction though up to now they've restrained the urge to unleash them. What we're bringing to Afghanistan now in some peoples' view is a form of terrorism, limited though it is. When does a weapon like the bunker buster or daisy cutter start to earn the distinction of "weapon of mass destruction?" And if we develop low-yield nuclear weapons, will these conventional megabombs rival their nuclear brothers in destructive outrage? Thanks much.

Jim Walsh: Well I certainly hope that we do not develop new mini-nukes or other nuclear weapons as that will compromise our legal commitments under the Nuclear Non-proliferation Treaty and reduce the likelihood of achieving a comprehensive test ban treaty. Without a strong NPT and test band treaty it is very unlikely that we will be able to stop the spread of nuclear weapons. I am sympathetic to the questioners concerns about highly destructive conventional weapons but as a matter law and customary usage the phrase "weapons of mass destruction" refers to chemical, biological and nuclear weapons.

Boulder, Colo.: What measures do you think should be taken to overcome Iraqi non-compliance with U.N. inspection of weapons sites?

Jim Walsh: I welcome President Bush's call for renewed weapons inspections in Iraq. Saddam Hussein has a clear record of both pursuing and in the case of chemical weapons using weapons of mass destruction. His continued tenure in Iraq represents an ongoing proliferation threat.

Jim Walsh: President bush has called on Saddam to meet his obligations under UN and international law and I agree with the president hat countries must respect its international obligations when comes to arms control and disarmament, and that would apply the U.S. as well.

Milwaukee, Wis.: What's the real deal on these "suitcase nukes?" I've read conflicting reports about a number missing from Russian inventories and about their serviceability if they are, in fact, on the loose. If they are a threat, how much?

Jim Walsh: The controversy regarding suitcase nukes began with comments by the Russian official Alexander Lebed who claimed that such weapons were missing from the soviet stockpile. He later backed off those claims. Most people who study this issue believe that Russia nuclear weapons - as distinct from Russian nuclear materials - are fairly secure. Claims that dozens of weapons are missing is more likely the result of bureaucracies using different counting methods than it is the result of weapons theft. Most Russian weapons like American weapons have devices that are intended to prevent unauthorized use even if they are to fall into the hands of third parties.

Jim Walsh: The news about radiological weapons is scary, but it is not all bad news. Radiological weapons are not nuclear weapons - Hiroshima type weapons. If used, their impact will likely be limited. They are intended to cause terror or fear and disruption.

The good news is that there is something that we can do to limit the risk posed by the weapons. First, we can do more to prevent nuclear weapons and nuclear materials from falling into the hands of terrorists. We can do much more than we are currently doing to protect nuclear materials in the U.S., in Russian and around the world. In addition, we should be doing more to stop and reverse the spread of nuclear weapons. As long as there are thousands of nuclear weapons and metric tons of nuclear material scattered across the globe there is always the risk that one day a terrorist will unleash the power of the atom.

Secondly, if a radiological weapon is used it will be up to Americans to define the real consequences of their use. Radiological weapons, like anthrax in letters, are intended to make people panic. Following the use of a radiological weapon, if the American public and the media overreact and submit to hysteria then this will only increase the chance that these weapons will be used again in the future. If, on the other hand, we recognize that radiological weapons are not nuclear weapons and respond appropriately terrorists will have little incentive to try and use them in the future.

The future is for Americans to decide and the time to decide that future is now.