National defense
(e) “National defense” shall mean (1) the operations and activities of the armed forces, the Atomic Energy Commission, or any other Government department or agency directly or indirectly and substantially concerned with the national defense, (2) other operations and activities directly or indirectly and substantially concerned with the operations and activities of the armed forces and the Atomic Energy Commission, (3) activities in connection with the Mutual Defense Assistance Act of 1949, as amended, or (4) the provision of community facilities or services necessary to the health, safety, or public welfare of the inhabitants of a town or community which has been relocated as a result of the acquisition (through eminent domain or purchase in lieu thereof) of its former site by or on behalf of the Atomic Energy Commission for national-defense activities.