Internal security -- National security -- 6 Emigration and immigration 3 Government publications -- 3 Law and legislation -- 3 Security clearances -- 3 Territorial waters -- 3 more ... Civil defense -- 2 History -- 2 Military policy 2 Police -- 2 Politics and government 2 Subversive activities -- 2 Terrorism -- 2 Anti-communist movements -- 1 Armed Forces 1 Civil rights -- 1 Civil society -- 1 Communism -- 1 Communist parties -- 1 Community policing -- 1 Congresses -- 1 Congresses. -- 1 Defense industries -- 1 Economic conditions 1 Education -- 1 Electronic surveillance -- 1 Environmental conditions 1 Government policy 1 History 1 less ...