Secret service History 40 World War, 1939-1945 37 Intelligence service 22 Politics and government 14 Espionage, Soviet 10 Military intelligence 9 Spies 9 Cold War 7 Internal security 7 Strategy 4 Campaigns 3 Cryptography 3 Police 3 Abuse of administrative power 2 Espionage, Russian 2 Foreign relations 2 National security 2 Peacekeeping forces 2 Political persecution 2 Presidents 2 Prevention 2 Smiley, George (Fictitious character) 2 State-sponsored terrorism 2 Terrorism 2 Underground movements 2 Women spies 2 World War, 1914-1918 2 Afghan War, 2001- 1 Army 1