<< "A bad job may be all that's necessary to sow panic and disruption," he noted, even if the attack itself produces "a mere handful" of fatalities or serious infections. >>

This is the key point, not made often enough IMHO. --Andre

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Headline: Experts Call for Better Assessment of Threats

Source: New York Times, 2 October 2001

URL: http://www.nytimes.com/2001/10/02/science/02THRE.html

Federal agencies and Congress are racing to check the security of everything from soybeans to municipal water supplies to nuclear reactors to whole cities. Last week, concern rose with the disclosure that the suspected jet hijackers had investigated crop-dusters — and thus, conceivably, the possibility of spreading deadly germs or chemicals.

"Terrorism is a clear and present danger to Americans today," Attorney General John Ashcroft told the Senate Judiciary Committee a week ago. On Sunday, Mr. Ashcroft renewed the alert, saying American retaliatory strikes might cause the already sizable risk of terrorism to rise.

But some private and public experts, including Congressional investigators who examined secret federal data, say American intelligence officials, for example, have at times exaggerated the risk posed by terrorists armed with weapons of mass destruction, which by definition can maim or kill tens of thousands or even millions of people. They say there are daunting obstacles to making and deploying these germ, chemical or radiological weapons.

That is not to say they dismiss chances of serious terrorist attack. But they regard more mundane instruments — firearms, car bombs or even hijacked truckloads of hazardous wastes — as more credible threats.

Federal officials reject such criticism. Though they say they have no knowledge of imminent threats from weapons of mass destruction, they say the danger is real and rising. And experts agree that the surprise attacks on some of the nation's most important buildings on Sept. 11 show the difficulty of anticipating all threats.

The dispute is throwing light on an obscure speciality of military theorists: threat assessment.

More art than science, the discipline relies on technical knowledge of what is possible and inferences about what resources terrorists have — money, materials and expertise — leavened with as many intelligence clues as possible as to their aims and goals. The field is rife with uncertainties, disagreements and, most basically, the challenge of disentangling vulnerability from real danger.

"You get the best and brightest and do your level best," Representative Sherwood Boehlert, a New York Republican who is chairman of the House Science Committee, said in an interview. "It's anything but simple."

Over the past few years, a growing number of federal agencies in charge of intelligence, agriculture, health, emergency preparedness and law enforcement have undertaken their own civil threat assessments. But they often disagree. And how fully they share information is unclear.

Federal threat assessments are sometimes kept secret to prevent foes from gaining possibly useful information from them. So the details of some remain unknown. But the General Accounting Office has reviewed them all, and its assessment of the assessments offers a window into this arcane world.

David M. Walker, who as comptroller general heads the General Accounting Office, testified recently before Congress that drawing up a comprehensive assessment of likely terrorist threats "has become an urgent imperative."

Some experts in and out of government say the assessments have often tended to be alarmist. The risk of a terrorist striking with weapons of mass destruction, they say, is lower than generally perceived and at times claimed in departmental appraisals.

It is extremely difficult, they insist, to acquire and use the complicated equipment needed to scatter deadly pathogens, chemicals or radioactivity in devastating ways. All too often, these critics say, assessments inaccurately miscast terrorists as technical sophisticates.

"There is an ocean of difference between learning how to steer a jetliner into a building and overcoming the technical hurdles in the dispersal of a biological agent to cause mass casualties," said Dr. Amy E. Smithson, an expert on chemical and biological weapons at the Henry L. Stimson Center, a private group in Washington that studies military assessments.

Dr. Brad Roberts, a terrorism expert at the Institute for Defense Analyses, a private group in Alexandria, Va., that advises the Pentagon, said experts were so shaken by the recent attacks that they now tended to see only worst-case scenarios.

"It's mostly `The sky is falling,' " he said. "I don't find many people sketching out the middle ground."

Even so, most experts agree that the risks of serious attack are destined to rise slowly over the years and decades as science, technology and arms expertise spread around the globe, making accurate assessment of them all the more crucial.

"Anybody who knows what's possible knows this could get a lot worse," Dr. Roberts said.

The roots of superterrorism lie in the success of modern science in producing lethal armaments. None, however, are easy to obtain. Nuclear weapons require mines, reactors and huge factories, putting their acquisition beyond all but nations. Chemical and biological arms are cheaper and easier to build, if the raw materials are obtainable.

Germ weapons, pound for pound, are usually the most potent, in some cases surpassing chemical and nuclear arms in terms of killing power. But they, too, are difficult to use. After the end of the cold war, and particularly after the breakup of the Soviet Union, many Western security experts warned that the means of mass destruction could fall into terrorist hands.

Alarms rang loud only after Aum Shinrikyo, a Japanese cult, attacked Tokyo subways with sarin nerve gas in 1995, killing 12 people and sickening hundreds. Investigators found the cult had already unsuccessfully launched germ attacks meant to kill millions of people. Its chosen banes included anthrax and botulinum toxin, the deadliest poison known to science.

Congress and the Clinton administration launched an antiterrorism push whose annual budget eventually hit $10 billion.

As spending rose, Congressional investigators in the General Accounting Office began to question existing agency threat assessments, many of which were not in accord.

For instance, the Federal Bureau of Investigation ignores smallpox as a major danger, possibly because the virus was eradicated from human populations decades ago and would be, theoretically at least, difficult to obtain. But the Centers for Disease Control and Prevention sees smallpox as a top threat. One reason: If unleashed, the virus can spread rapidly because of its extreme contagiousness.

A lengthy G.A.O. report in September 1999 found some threats plausible and others doubtful. The report saw more risk from substances already in wide use, like chlorine, an industrial gas that is highly toxic. But the report ranked most germ agents as only possible or unlikely threats.

"Although most biological agents are easy to grow if the seed stock can be obtained," Henry L. Hinton Jr., a G.A.O. official, said at a House hearing in October 1999, "they are difficult to process into a lethal form and successfully deliver to achieve large- scale casualties." For instance, he said, the microscopic particles of an infective mist had to be just the right size to penetrate deep into human lungs and start infections.

In July 2000, the G.A.O. faulted the nation's spies, saying intelligence officials at times falsely portrayed chemical, biological, radiological and nuclear arms as easy for terrorists to make and use. The lack of caveats, Norman J. Rabkin, a G.A.O. official, told a House subcommittee, may give policy makers in Congress and the administration "an exaggerated view" of the mass-destruction threat.

But intelligence officials denied any embellishing. In interviews, they noted that George J. Tenet, director of Central Intelligence, last year warned Congress that terrorists were exploring how "rapidly evolving and spreading technologies might enhance the lethality" of strikes and that operatives of Osama bin Ladin "have trained to conduct attacks with toxic chemicals or biological toxins."

With national jitters high after the Sept. 11 attacks, many people are making informal judgments about what attacks might come next. Security experts, while often disagreeing over long-term trends and dangers, say most of these snap calls are overreactions.

It is unlikely now, they say, that terrorists could steal an atomic bomb, buy one on the black market or crash a jet into a nuclear reactor to produce a radioactive cloud.

Anxiety nonetheless abounds. "Sales are up," said Dan Sythe, president of International Medcom, a company in Sebastopol, Calif., that makes radiation detectors. "People are concerned about nuclear terrorism."

Experts agree that the easiest nuclear weapon to acquire would be radiological, sometimes known as a "dirty nuke." These use conventional high explosives to scatter highly radioactive materials to poison targets rather than destroying them with blast and heat. Their effects on people range from radiation sickness to cancer.

Iraq tested such a bomb in 1987 but scrapped the project as too hard, the radiation levels too low.

"At worst, a dispersal device could create a lot of panic," said Dr. Frank von Hipple, a physicist who advised the Clinton White House and now teaches science policy at Princeton. "It's more a psychological weapon. My chances of getting cancer might increase from 20 to 20.5 percent." He added that federal officials are "overdoing the warnings, in terms of panicking people."

People are also stocking up on bottled water, fearful that terrorists could poison reservoirs. But germ warfare experts dismiss such threats as verging on the impossible.

"Municipal water supplies are very difficult to contaminate to cause widespread casualties," Frederick R. Sidell, William C. Patrick III and Thomas R. Dashiell wrote in "Jane's Chem-Bio Handbook," a 1998 reference used by the police, doctors and firefighters. "Dilution and diffusion factors as well as chlorination combine to make this type of operation nonfeasible."

Perhaps the greatest current fear is that terrorists will lace the air with lethal germs. The news that some of the accused hijackers had investigated crop-dusters caused a stir because experts had long identified the agricultural craft as a possible way to spread deadly pathogens.

Dr. Michael T. Osterholm, an epidemiologist, warned of such an attack in his 2000 book, "Living Terrors: What America Needs to Know to Survive the Coming Bioterrorist Catastrophe." He envisioned a crop- duster attacking a stadium with anthrax, infecting 54,000 fans and nearby people. The disease of coughing and high fevers is usually fatal unless treated soon after exposure.

But in his book, Dr. Osterholm conceded that a number of factors, most especially fickle winds, make such an attack "a risky proposition."

Other hurdles include getting the right strain, or subspecies, of the germ. Experts say Bacillus anthracis comes in scores of different ones, most of which would likely produce a weak or ineffectual weapon. If able to brew up swarms of lethal microbes — a dangerous process — a terrorist would have to coax the fragile rod-shaped bacteria into forming spores, a hardy, hardened, dormant state. Doing so can be a tricky step involving heat or chemical shock.

Even with a supply of deadly bugs, a terrorist would face dispersion hurdles. For instance, commercial crop- dusters usually dispense liquids, and their nozzles produce droplets far too large to get deep into human lungs. A terrorist would have to do major modifications to adapt the sprayer's nozzles to produce a finer mist of particles.

Dr. Richard Spertzel, a former head of biological inspections in Iraq for the United Nations, said Baghdad tried to make such nozzle modifications before the Persian Gulf war but encountered great difficulties and was forced to buy needed parts abroad.

Experts say dry anthrax is even more difficult to make than the wet variety but is better for attacks because it can sail farther on the wind. However, shifting winds can also complicate anthrax attacks, especially in urban areas. Cities generate heat, and rising air currents can carry anthrax germs high into the atmosphere, diluting the cloud of microbes and making them less likely to kill. It takes an estimated 8,000 to 10,000 anthrax germs lodged in the human lung to start a lethal infection.

"People don't understand how difficult it is to pull off a biological attack," said Dr. David R. Franz, a former top official in the Army's germ-defense program and now an officer at the Southern Research Institute, an arm of the University of Alabama.

Dr. Steven M. Block, a germ-terror expert at Stanford, agreed. "A crop- duster is likely to do a very bad job," he said. But he noted that fears rooted in unrealistic appraisals of the germ threat can greatly magnify an assault's effectiveness.

"A bad job may be all that's necessary to sow panic and disruption," he noted, even if the attack itself produces "a mere handful" of fatalities or serious infections.

-- Andre Weltman (aweltman@state.pa.us), October 02, 2001