sentences:  The 1925 Geneva Protocol, ratified by most major powers in the 1920s and 30s, had still not been ratified by the United States at the dawn of World War II.Among the Protocol's provisions was a ban on bacteriological warfare.The Geneva Protocol had encountered opposition in the U.S. Senate, in part due to strong lobbying against it by the Chemical Warfare Service, and it was never brought to the floor for a vote when originally introduced.