United States History 189 Foreign relations 129 Biography 124 Politics and government 84 Military policy 51 Terrorism 44 Armed Forces 34 Presidents 33 Prevention 29 Juvenile literature 26 World War, 1939-1945 24 World politics 24 National security 22 Sources 20 History, Military 18 Social aspects 18 War on terrorism, 2001- 18 Case studies 17 Civil War, 1861-1865 17 Generals 17 Campaigns 14 Intelligence service 14 Leadership 14 Social conditions 14 Soviet Union 14 Cold War 13 Relations 13 Army 12 Great Britain 12