The Geneva Protocol was ratified the 17 June 1925, banned the use of biological weapons but Japan refused to approve the contract and the U.S. to ratify it.

Therefore in 1936 Shiro Ishii (1892 -1959) physician, microbiologist and general Japanese, guided the biological weapons program of the Empire of Japan, under the command of a military unit called Research Unit 731.

Unit 731 was established in 1932 and gave birth to an organization sponsored by the State and dedicated to biological terrorism and mass murder, with workshops and camps scattered in the huge empire that Japan had in the 'East Asia.

Ishii builds a complex of 150 buildings, near Harbin, Manchuria, for experimental purposes, here die more than 9000 people used as guinea pigs.

Another site, Unit 100, is established in Changchun.

Ishii tests his methods on the Chinese military and civilians, tens of thousands of them die for plague, cholera, anthrax.

One method was to fly over an area, making fall wheat mixed with infected fleas that infect rats attracted to the grain, and became reservoirs of plague, including it in human populations. In  October 1940, the Japanese spread by air of Yersinia pestis on Chuhsien  and on Ninpo, has caused 120 deaths.

The plague is diffused  by the Japanese moreover in the provinces of Suiyuan and Ninghsia with subsequent serious epidemic (1941).

In the years 1941-1942, the G.B. makes experiments with anthrax on Scottish islands. Forty years later (1982) Insland Gruinard is still heavily contaminated.

Despite all attempts to disinfect the island, the spores of this experiment have led to quarantine them for 48 years, until 1990. In 1986 a specialized company was paid half a million pounds to decontaminate the 520-acre island, scattering on the ground 280 tons of formaldehyde in dilute 2000 tons of seawater. 

Today if someone dispersed in the atmosphere the anthrax bacteria near a city of 500 thousand inhabitants, could cause the death of over 90 thousand people within a week. "It should be remembered- as says Graham Pearson, University Professor of International Security of Bradford - that biological terrorism is a major threat to our world"