The greatest terrorist threats today are biological agents.

Biological agents are easily accessible, almost impossible to detect, and extremely deadly. Listen to the words of terrorism expert Peter Probst, from a mid-1990s speech: "Only a few grams of pulmonary anthrax, which has something on the order of a 95 percent lethality rate, could take out a major government complex. Similarly, a vial of such an agent dropped from the Senate gallery could take out much of this country's leadership."

Probst, an ex-CIA employee who has spent more than two decades developing antiterrorism plans for the U.S. Department of Defense and others, says that "the terrorist weapon of the future could, at first glance, appear to be an ordinary light bulb, which, in turn, is a preferred covert delivery method for biological agents. Terrorists could take several such devices filled with pulmonary anthrax and toss them onto the tracks of the Washington Metro. The bulbs would shatter, and lethal spores would be carried throughout the system by the convection currents of passing trains. They would cling to the clothing and shoes of the subway commuters who would track it into their homes and offices. Thousands would aspirate the deadly spores. Thousands would die."

The U.S. is extremely vulnerable in the event of germ warfare.

According to Dr. Ken Alibek, the first deputy chief of the secret Soviet germ-warfare program from 1988 to 1992, nations like Iraq, Afghanistan, Iran, Sudan, and Yemen have lured away and hired Soviet scientists who are knowledgeable in biological weapons. Alibek, who defected to the U.S. in 1992, says it's "highly probable" that terrorists already have obtained Soviet chemical, biological, and nuclear weapons. And the things they have procured are awful in their magnitude. According to Alibek, the Soviet Union has developed strains of anthrax, plague, and other infectious and deadly diseases—including tularemia and glanders—that can't be treated with antibiotics.

If you're in the market for germs, just place an order.

White supremacist Larry Wayne Harris recently had some official-looking letterheads made, and then ordered three vials of bubonic plague from a Rockville, Maryland, laboratory. The plague samples were delivered by Federal Express. Interestingly, it's not illegal to possess bubonic plague. Harris was nonetheless caught by law enforcement officials and convicted of mail fraud for ordering the samples with fake stationery. His sentence? Eighteen months' probation. If you don't want to order the stuff already made, you can get various recipes from easily obtainable sources. When the white supremacist group known as the "Patriot's Council" wanted to get the formula for recin, another deadly biological agent, it reportedly found what it needed in a Soldier of Fortune magazine advertisement. A Soldier of Fortune spokesman, however, does not recall the incident.

Numerous experts were predicting an event similar to the suicide bombings. But you won't hear that from the Pentagon.

In testimony before the U.S. Senate Judiciary Committee in 1996, another terrorism expert, Steve Emerson, predicted last Tuesday's events with deadly accuracy. "The United States will, in my opinion, increasingly serve as a lightning rod for international terrorists who perceive the U.S. as an enemy that must be destroyed because of its inherent evil nature," Emerson testified. He also told the senators that "terrorists will attempt to carry out attacks that will generate mass casualties and fatalities." He predicted that the terrorists "will most likely target office buildings or arenas housing large civilian populations." Owing in large measures to his views, Emerson has been branded a racist and an alarmist who relies on questionable sources and shoddy research techniques. Before the September 11 bombings, he was so hard up for cash that he was cold-calling would-be donors in an effort to keep open his antiterrorism outfit, Investigative Project on Religious Extremism. But now, because of the bombings, Emerson is so much in demand that he's lucky to get two hours' sleep a night.

In the early 1990s, terrorism expert Probst coauthored an extraordinary Pentagon report, "Terror 2000: The Future Face of Terrorism," which outlined and predicted the events of last week with alarming accuracy, according to those who've obtained copies. But you can't read the report. The Pentagon never released it to the public.

As the nation mourns, there is a natural tendency to want to figure out precisely what happened. Unfortunately, this often leads to fighting yesterday's war. Vanderbilt University political science professor Jim Ray, a specialist in international conflict, rightly points out that, as a nation, we'd be well served to focus on "less obvious" sources of potential trouble.

Nashville Scene senior writer Willy Stern is a former staff writer at Forbes and Business Week magazines. For a complete version of this story see www.nashscene.com.