As authorities work to uncover the source of the anthrax that is tainting a growing number of mail facilities from the US Supreme Court to the CIA, they are simultaneously facing an even more daunting task: preparing for what might come next.
The seriousness of the anthrax threat and concerns that Al Qaeda cells may be planning another wave of attacks are making the effort to keep dangerous materials out of the hands of terrorists in the first place an urgent national-security priority.
Guarding against every potential threat may well be impossible - there are simply too many ways terrorists might strike. Good intelligence will be essential to thwarting any attack. But experts say the US can take steps to prevent some of the most dangerous threats through tighter security at biological, chemical, and nuclear plants worldwide.
In the case of smuggled nuclear material, better screening at ports and airports might help. And a fast and effective response can greatly minimize and contain the damage in the case of a biological or chemical attack.
"We detected everything that was going to happen at the millennium, and nothing happened. That was wonderful," says Fred Iklé, a former undersecretary of Defense in the Reagan administration. "We did not detect things before Sept. 11. So it's a risk you cannot clearly define. You can, however, reduce it."
The need for unprecedented vigilance is becoming clearer in the wake of the bioterror attack. The anthrax sent to Sen. Tom Daschle - now characterized as unusually fine and even having its electrostatic charge removed - suggests a sophisticated culprit.
While this could be anyone from a lone microbiologist working in a well-equipped lab to a state-sponsored terrorist group, it means the attacker may also harbor the ability to carry out a broader biological assault, using either anthrax or another agent, such as smallpox.
Other scenarios officials are concerned about range from a possible chemical attack to poisoning of the nation's food supply (Health and Human Services Secretary Tommy Thompson has said he is "more fearful" about the food supply than anything else) to a cyberattack - what experts refer to as a "weapon of mass disruption."
Recently, unconfirmed reports have suggested that Osama bin Laden's network may even possess radioactive material, adding to concerns about an eventual nuclear attack.
Holes in the Russian system
One of the biggest threats, experts agree, is the lack of security at weapons facilities in the former Soviet Union. At many Russian plants, few safeguards exist to prevent a worker from stealing materials. Under communism, this didn't matter, because no one could leave the country, and any worker meeting with a foreigner would be closely watched by the KGB. Now it's a major danger.
"Hundreds of tons of potential bomb material in the former Soviet Union, and smaller quantities in a variety of other countries worldwide, are dangerously insecure and poorly accounted for," says Matthew Bunn, a nuclear-weapons expert at Harvard University in Cambridge, Mass. "A similar situation pertains to the biological facilities, for the chemical facilities, and so on."
Although Russia says it has destroyed its stocks of biological weapons, Mr. Bunn says international visitors have not been allowed to enter a number of former bioweapons facilities - "and so what exactly is going on there is somewhat unclear." Likewise, many of the thousands of scientists who worked in the Soviet bioweapons program at its peak are now unaccounted for and may be employed in other countries, such as Iran, Iraq, or Libya.
"Some of these Soviet scientists who have not been able to make a living since the Soviet Union broke up probably have gone over [to Iraq] and filled in the knowledge gaps for them," says Bill Patrick, chief of product development for the US bioweapons program before it was disbanded in 1969. "That's scary, because the Soviet Union had a very advanced, very productive bioweapons program."
The concern is not only that Russian scientists may be working for rogue regimes, but that they may have taken some raw material with them. The smallpox virus, for example, is known to exist in only two labs - one in the US (at the Centers for Disease Control in Atlanta) and one in Russia. But experts say there's no way of knowing whether some of the Russian stock could have been stolen and grown elsewhere.
The threat is serious enough that the US government has already rushed to stockpile the smallpox vaccine, ordering more than 300 million doses, enough for every American, to be available in a year. Smallpox is considered a potentially more devastating bioweapon than anthrax, because it is contagious.
Still, medical experts note that if the vaccine is administered within three to five days of infection, the effects can be mitigated and the outbreak contained. This means a strong public-health system, including doctors who are trained to spot patterns of symptoms, is crucial.
By contrast, if a nuclear attack were to occur, little can be done afterward. This makes it all the more important, say experts, to protect existing nuclear material in Russia and elsewhere. Efforts like the Nunn-Lugar Cooperative Threat Reduction program are addressing the problem, but only about 40 percent of the nuclear material in Russia will be secured by the end of 2001, says Bunn.
If terrorists do get ahold of radioactive material, there's no guarantee they'd be able to construct a nuclear weapon. But even a crude bomb could do a lot of damage. While they'd still have to smuggle it into the US, this may not be difficult, since only about 5 percent of shipping containers get inspected.