Abstract: The Ryukyu Islands were the largest U.S. overseas military base of chemical weapons storage during the Cold War. Ryukyu Islands Chemical Weapons Leak Incident occurred under the dual background of the U.S.-Japan negotiation on the Administrative Power of Ryukyu Islands Reversion and the Nixon Administration's formulation of the U.S. Policy on Chemical Weapons. The Nixon Administration immediately directed the removal of lethal chemical munitions from Ryukyu Islands to CONUS for the redeploy. This was strongly resisted by some members of the U.S. Congress and local governments in Oregon and Washington. The Nixon Administration's approach to dealing with chemical weapons issue was very different from the nuclear weapons issue during the negotiation on the Ryukyu Islands Reversion, neither seeking the right to redeploy chemical weapons nor requiring financial compensation. Such practice was not only determined in NSDM 35, but also was an example of dealing with chemical weapons at the U.S. Military Base in Federal Republic of Germany (FRG). The Military Procurement Act of FY1970 and FY1971 passed by the U.S. Congress has strictly restricted the Pentagon's authority in the research, storage, transportation, testing and procurement of lethal chemical weapons in national legal system.

Key words: chemical weapons, Ryukyu Islands, public law, Military Procurement Act, Nixon