Beginning in the late 1960s, the chemical warfare capabilities of the United States began to decline due to, in part, a decline in public opinion concerning the corps. The corps continued to be plagued with bad press and mishaps. A 1969 incident, in which 23 soldiers and one Japanese civilian were exposed to sarin on the island of Okinawa while cleaning sarin-filled bombs, created international concern while revealing the presence of chemical munitions in Southeast Asia. The same year as this sarin mishap, President Richard Nixon reaffirmed a no first-use policy on chemical weapons as well as renouncing the use of biological agents. When the U.S. BW program ended in 1969, it had developed seven standardized biological weapons in the form of agents that cause anthrax, tularemia, brucellosis, Q-fever, VEE, and botulism. In addition, Staphylococcal Enterotoxin B was produced as an incapacitating agent.