"The Federal Civil Defense Administration was guided by three major principles during fiscal year 1957: (1) Civil defense is part of the inherent responsibility of government at all levels to prepare for emergencies. (2) The destructive power of nuclear weapons demands that there be close cooperation among many governmental jurisdictions for effective civil defense operations. (3) Close cooperation between officials responsible for the military and the civil defense of the Nation is essential". (FCDA, Annual Report 1957, page vii) An operations plan for a hypothetical metropolitan target area was developed by FCDA and distributed to Government officials throughout the country. The plan, entitled Batleground, USA shows how the principles and concepts of national civil defense planning can be applied at the local level. (FCDA, Annual Report 1957, page 1) Both the Department of Defense and the Federal Civil Defense Administration intensified efforts during fiscal year 1957 to improve coordination of their respective roles and operations in natural disasters and in emergencies caused by enemy action. Early in the year the Department of Defense revised its basic directive relating to the responsibilities of the armed services for civil defense and other domestic emergencies to reflect a stronger and more positive role. (FCDA, Annual Report 1957, pp. 10-11) Civil Defense Act of 1950 (Public Law 81-875)