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The Growing Threat of Biological Weapons

The terrorist threat is very real, and it's about to get worse. Scientists should concern themselves before it's too late

Steven Block

The World Wars

The First World War saw one of the first attempts to use anthrax during warfare, directed??ineffectively??against animal populations. Instead, WWI became infamous for its introduction of poisonous mustard gas, which was used effectively against humans. (By odd coincidence, WWI also overlapped with a deadly outbreak of influenza, the Great Pandemic of 1918, which eventually killed more people than the Great War itself.) International revulsion at the horrors of WWI led to the signing of the Geneva Protocol of 1925, which went into force on February 8, 1928, with 29 participating nations, including the U.S. The treaty contained "A Protocol for the Prohibition of the Use in War of Asphyxiating gas, and of Bacteriological Methods of Warfare."

Although the Geneva Protocol didn't expressly forbid the production and development of biological weaponry, it did ban all use during war. Disappointingly, neither the U.S. nor Japan ratified the treaty before the advent of World War II, when anthrax and other bioweapons were secretly being developed by both countries??as well as by Germany, the U.S.S.R. and Great Britain. The Japanese and British bioweapons programs were particularly extensive, but no documented use of agents ever occurred during combat. This may have been due to residual respect for the 1925 treaty or, what seems more likely, from the relative immaturity and associated imperfections of bioweapons technology.

There were some notorious instances of biological warfare during this period, however. The Japanese Military Unit 731 at Ping Fan, Manchuria, experimented extensively with bioweapons, killing thousands of prisoners of war with anthrax, cholera, plague, dysentery and other infectious agents. They also released plague on the Chinese civilian population of Chekiang Province on several occasions by dropping from airplanes laboratory-grown fleas fed on infected rats. The Soviets may have deliberately infected German Panzer troops with tularemia during the Battle of Stalingrad in 1942, by far the costliest battle of WWII, but the ensuing outbreak soon spread to both sides and resulted in more than 100,000 cases of the disease.

Figure 2. Historical incidents involving biological weaponsClick to Enlarge Image

Unlike the years following WWI, the post-WWII period heard little public debate concerning the need to limit bioweapons??perhaps owing to the global preoccupation with nuclear arms that began in 1945. With the advent of the Cold War, the U.S. biowarfare program (begun in 1942 and aided by postwar intelligence from the Japanese) went into overdrive. Over the course of the next 25 years, the U.S. would quietly develop, test and weaponize at least 10 different biowarfare agents, including bacteria, viruses and microbe-derived toxins. The U.S. not only experimented with human disease, but also targeted economically vital agriculture with fungal weapons such as wheat rust and rice blast. The Soviets had a program that was every bit a match for the American one, but concentrated on a different subset of diseases. Both countries stockpiled plenty of anthrax.

A good deal of effort on both sides went into attacking the problem of weaponization. Biowarfare agents may be deadly, but they are also labile and difficult to deliver to the intended target. It took years of experimentation before the U.S. and Soviet programs eventually succeeded in developing effective means of stabilization and distribution??in the form of explosive bomblets or aerosol-spray weapons that could be delivered by aircraft or ballistic missiles. Today, the operating principles of such delivery devices are among the most closely held national secrets. This is entirely appropriate, given the relative ease with which most other aspects of the bioweapons problem are tackled.

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