Biological weapons are any infectious agents such as bacteria or viruses used intentionally to inflict harm on others. Armies and terrorists use them for mass destruction. Some of the viruses put in bio-weapons are Anthrax, Bubonic Plague, Ebola, Smallpox, and many, many others. Viruses are put in missiles. When the missile hits and explodes the virus is released and spreads. This can kill many people and infect even more. Anthrax and Ebola are very deadly and  if they were ever used in war or in terrorist acts the result would be horrible. Bio-weapons are very a loathsome instruments of war. Bio-weapons have been used since 6th century B.C. when Assyrians poisoned their enemies water hole with rye ergot. The United States Army estimated that just two airplanes each only carrying 10,000 pounds could kill 60 million Americans. The  Secretary of Defense, William Cohen, has stated that just 5 pounds of Anthrax from Iraq could be used to wipe out half the population of Washington D.C. Nations that are not wealthy in resources or technology could easily produce or get bio-weapons. This is a cause of great concern. One of the principal causes of tension between the United States and Iraq is the production of bio-weapons in Iraq.