Although military law enforcement's jurisdiction is generally limited to military installations and facilities, its jurisdiction may also follow military personnel and Department of Defense special interests wherever they are found. This differs from civilian law enforcement jurisdiction, which is strictly defined by geographical borders. The authority of military police is governed by the provisions of the Uniform Code of Military Justice (UCMJ). Although the UCMJ includes crimes punished under civilian law, it goes beyond civilian law to punish other conduct that affects good order and discipline in the military. In the area of operations, military security forces have the additional responsibility of being responsible for the national defense mission of the U.S. Government. The similarities between civilian and military law enforcement, however, are sufficient to provide areas where cooperation can improve public safety. Community policing, crime prevention, traffic control and management, and efforts to combat domestic violence are but a few of the law enforcement responsibilities held in common by civilian and military law enforcement personnel. The various military criminal investigation organizations also mirror the role of the detective cadre of a typical civilian law enforcement agency. The first step in achieving cooperation is for either a military or civilian law enforcement executive to identify his/her counterpart in a jurisdiction and contact him/her for the purpose of meeting to become acquainted and discuss one another's roles and how cooperation can facilitate the operations of each agency. At some point, attention should be given to common areas of policy, planning, communication, exchange of information, and training. Some areas of cooperation might be memorandums of understanding, incident planning and response, the definition of jurisdictional issues, the creation and sharing of a phone listing of important joint contacts within respective agencies, the handling of cases that involve military dependents and dependent juveniles who live off base, handling procedures for military personnel arrested off base or civilians arrested on the base, and how and when staff should communicate with one another. Another area of cooperation involves information-exchange structures and parameters. In the latter area, information should be exchanged on specific crimes or intelligence related to the protection of law enforcement personnel and the citizens they serve. This article suggests ways in which a positive working relationship can be enhanced and sustained once organizational ties have been established. Success in cooperation at local levels can lead to greater cooperation at the national level. The International Association of Chiefs of Police has a broad range of resources available to aid in establishing and enhancing cooperation between civilian and military law enforcement agencies.