FREEDOM TO OPERATE. “Both the U.S. bio-weapons ban and the Biological Weapons Convention restricted any work in the area of biological warfare to defensive in nature. In reality, this gives BWC member-states wide latitude to conduct biological weapons research because the BWC contains no provisions for monitoring of enforcement. The treaty, essentially, is a gentlemen’s agreement amongst members backed by the long-prevailing thought that biological warfare should not be used in battle.”
http://en.wikipedia.org/wiki/US_Biological_Weapon_Testing