The countries that signed the Geneva Protocol at the Geneva Convention include the United States, United Kingdom, France, Germany and Japan. Since 1925, more than 130 countries have signed the protocol.
The Geneva Protocol was an agreement between nations made after World War I that biological, bacteriological and asphyxiation could not be used against others whether or not in times of war. The treaty was written on June 17, 1925, and put into effect on Feb. 8, 1928. Most of the largest world powers signed the treaty except for Japan and the United States; the United States didn't ratify the treaty until Jan. 22, 1975. The ratification document was placed with the Government of France shortly afterward and proclaimed by the U.S. President on April 29 of that same year.
France was the first country to ratify the Geneva Protocol on May 10, 1926. Liberia ratified it the next year. Austria, Belgium, Egypt, Italy, Russia and Venezuela followed in 1928. Germany, Finland, Iran, Poland and Spain signed it in 1929. The United Kingdom didn't ratify it until 1930 along with Sweden, Australia, Canada, Denmark and the Netherlands. However, Canada signed with reservations that it did not remove until 1999. The United States was the only nation to ratify the protocol in 1975, although Barbados and Qatar signed it in 1976. The last country to sign as of 2015 was St. Vincent and the Grenadines.