History

The U.S. E133 cluster bomb was developed prior to Richard M. Nixon's 1969 declaration

Statement on Chemical and Biological Defense Policies and Programs

The "Statement on Chemical and Biological Defense Policies and Programs" was a speech delivered on November 25, 1969, by U.S. President Richard Nixon. In the speech, Nixon announced the end of the U.S. offensive biological weapons program and reaffirmed a no-first-use policy for chemical weapons...

 that ended the U.S. biological weapons program. At the time of Nixon's declaration the E133 was considered the most likely candidate in the U.S. biological arsenal to actually be used in a combat situation.

Specifications

The E133 cluster weighed 750 pounds. It held between 536 and 544 E61 bomblets, which when dropped would detonate on impact dispersing an aerosol of biological agent

Biological agent

A biological agent — also called bio-agent or biological threat agent — is a bacterium, virus, prion, or fungus which may cause infection, allergy, toxicity or otherwise create a hazard to human health. They can be used as a biological weapon in bioterrorism or biological warfare...

, usually anthrax

Anthrax

Anthrax is an acute disease caused by the bacterium Bacillus anthracis. Most forms of the disease are lethal, and it affects both humans and other animals...

.