History 1,043 Politics and government 893 Foreign relations 584 Economic conditions 268 Biography 222 World politics 219 World War, 1939-1945 203 Armed Forces 198 International relations 186 Terrorism 158 Military policy 156 Social conditions 147 Leadership 139 Congresses 132 Economic policy 130 Communism 118 National security 118 Campaigns 109 Management 105 Military art and science 102 Vietnam War, 1961-1975 98 War 87 Islam 75 Case studies 71 Political activity 69 Research 68 Relations 65 Defenses 63 Strategy 61 Security, International 60