Secret service History 2,205 World War, 1939-1945 1,790 Spies 809 Service secret 722 Intelligence service 664 Guerre mondiale, 1939-1945 413 more ... Politics and government 387 Histoire 341 Military intelligence 340 World War, 1914-1918 323 Espionage 310 Underground movements 221 Intelligence officers 211 Foreign relations 189 Internal security 168 Campaigns 139 HISTORY 139 Cryptography 136 Women spies 134 Espions 130 Police 114 Vietnam War, 1961-1975 113 Espionage, German 107 Espionage, British 101 Officials and employees 101 Espionage, Soviet 93 War 88 Social life and customs 78 Americans 76 less ...