13-21. Army forces may participate in interagency operations across the range of military operations, especially when conducting stability or defense support of civil authorities tasks. Frequently, Army forces conduct operations in cooperation with or in support of civilian government agencies. Relations in these operations are rarely based on standard military command and support relationships; rather, national laws or specific agreements for each situation govern the specific relationships in interagency operations. Defense support of civil authorities provides an excellent example. Federal military forces that respond to a domestic disaster will support the Federal Emergency Management Agency, while National Guard forces working in state active duty status (Title 32 United States Code) or conducting National Guard defense support of civil authorities will support that state's emergency management agency. National Guard forces federalized under Title 10 United States Code will support the Federal Emergency Management Agency. The goal is always unity of effort between military forces and civilian agencies, although unity of command may not be possible. Effective liaison and continuous coordination become keys to mission accomplishment. (See FM 3-28.)