Summary: In congressional testimony based on its recent report, GAO discussed the use of the military to assist Federal drug law enforcement agencies in drug interdiction efforts since the enactment of amendments to the Posse Comitatus Act in 1981. The amendments were designed to remove restrictions and ambiguities and to facilitate cooperation between military and civilian officials. As required by the amendments, the Department of Defense (DOD) established policies and procedures which stipulated that DOD cooperate with civilian law enforcement agencies to the maximum extent practicable, consistent with the needs of national security, military preparedness, and the historic tradition of limiting direct military involvement in civilian law enforcement activities. Several factors which continue to limit military assistance are: (1) incompatibility between military systems and activities and the needs of law enforcement; (2) a requirement that DOD obtain reimbursement under certain circumstances, which could strain civilian law enforcement budgets; and (3) the disclosure of classified information regarding the use of sophisticated military systems in criminal court proceedings. GAO anticipates that military assistance will increase in the future as defense and law enforcement agencies explore the possibilities for a coordinated attack on drug smuggling.