The ban on the use of chemical weapons, as codified in the 1925 Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases, and Bacteriological Methods of Warfare, is considered to constitute customary international law, applicable to all states regardless of whether they are parties to the Protocol.64 The possession of chemical weapons is prohibited under the 1993 Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction (the Chemical Weapons Convention), which is scheduled to come into force on April 29, 1997.65 As of January 27, 1997, out of 161 states that had signed the convention, sixty-eight states had submitted instruments of ratification.66 The Republic of Croatia ratified the Chemical Weapons Convention in May 1995. The Republic of Bosnia and Hercegovina and the Republic of Slovenia had both signed but not yet ratified the treaty in January 1997. At that time, neither the Federal Republic of Yugoslavia nor the Former Yugoslav Republic of Macedonia had signed the convention. Human Rights Watch holds that because of the grave threat chemical weapons pose to the people of the Balkans and in light of the well-documented abusive conduct of all sides during the war in Bosnia and Hercegovina, states of the former Yugoslavia should, regardless of treaty ratification, immediately end all production and development of chemical munitions, and declare and destroy existing stockpiles.

The international community has the capability and responsibility to investigate allegations of chemical weapons production and use. The U.N. Secretary General is charged by the U.N. General Assembly “to carry out investigations in response to reports that may be brought to his attention by any Member State concerning the possible use of chemical and bacteriological (biological) or toxin weapons...and to report promptly the result of any such investigation to all Member States.”67 Procedures for investigating such allegations were established in a report of the Secretary-General in 1989.68 Moreover, under the 1993 Chemical Weapons Convention, a new international agency is to be established, the Organization for the Prohibition of Chemical Weapons (OPCW), based in The Hague, after the treaty enters into force in April 1997. The OPCW is to be charged with implementing the provisions of the convention and providing a forum for consultation and cooperation among State Parties to the treaty. The OPCW is also to have a mandate to investigate allegations of chemical weapons production and use. In the view of Human Rights Watch, any investigation of chemical weapons production, stockpiling and use needs to be transparent and impartial, and be held to rigorous international standards.