The probability of U.S. forces encountering chemical or biological weapons during conflicts remains high. In reviewing DOD's readiness, the GAO found soldiers were better equipped for chemical and biological warfare than in the 1996 evaluation. At that time, many units did not have their required protective equipment or were inadequately trained in basic tasks critical to surviving and operating in chemical or biological environments. In the current review, the Army had all of their medical supplies and the Air Force wings had most of theirs. The Marine Corps had shortages in detection and decontamination equipment, but those shortages varied across the services and within a service. Commanders were not integrating chemical and biological defense into unit exercises, and the training was not always realistic in terms of how units would operate in war. For example, the Marine Corps did not integrate chemical and biological defense into exercises because it decreased the number of combat essential tasks that could be performed during an exercise and limited offensive combat operations. Chemical and biological defense training is being adversely affected by a shortage of chemical and biological defense specialists and specialists who are being assigned multiple responsibilities unrelated to their specialties. In April 2000, the Joint Chiefs of Staff required units to more clearly report on the quantity of chemical and biological equipment on hand. But the changes did not require that units report on the equipment's condition. The GAO recommends the military include realistic chemical and biological defense training in exercises and these exercises adhere to realistic wartime scenarios. The GAO also recommends the military include equipment readiness ratings. Tables, appendices